Interesting to see how the same request was "solved" totally different on Cloud:
https://community.atlassian.com/t5/Jira-Service-Management-articles/How-we-re-addressing-your-feedback-on-the-issue-create/ba-p/2161307

This was resolved as part of https://jira.atlassian.com/browse/JSDSERVER-1211 in JSD 3.7.0 and onwards.

Lachlan Goodhew-Cook
Jira Service Desk Server team

Isn't this issue solved?

Make sure you got the "Customer Request Type" field on the create issue screen. Then one get a dropdown menu to select the Request type.
Make also sure that you got a Request Type matching the Issue Type to be able to select it. I've solved this by having hidden Request types in the portal matching the Issue Type in the project..

Use of for example Automation can automatically set those Request Types to an Issue Type if the request type have been forgotten to be set on creation.

@timhagen Thanks, Tim.  All of these users DO have accounts in the portal.  The main issue is that they are so used to going into JIRA to create and edit issues that they aren't using the portal for their ServiceDesk requests, where all of the Customer Request Types are set up with the required fields, etc.  Several times a week I am asked by folks why they can't update their requests and upon investigation, it is only because they are doing it through the JIRA view instead of the portal.  I thought that an 'easy' way to do this would be to disable the ability for service desk customers to create issues anywhere but the portal, while allowing agents and admins to still create within the ServiceDesk queues, where they operate day in and day out.  However, that isn't a possibility, so I thought at least if we get the required fields (and customer request type) that may alleviate some of the pain as well.

@ljohnson, from JSD-1736: "As long as you add the users in these roles to the "Service Desk Customers" role, they can still create issues in the portal."

Does that solve the issue? I'm trying to solve the same problem, but I don't understand why an additional portal-only account would be required.

My organization has been using JIRA Software for several years and the entire organization is used to going to JIRA and hitting Create when they need a new issue created.  Now that we've introduced ServiceDesk, folks are still using this method to open issues in the ServiceDesk, causing the problems listed above with the missing fields and the ability to mismatch customer request types and issue types, required fields, etc.  Ideally, I would be able to simply hide my ServiceDesk project from the create button using permissions (our admins and ServiceDesk agents know this problem and will create an issue and immediately update the incorrect fields - yes, I'm lucky that way).  The workaround mentioned in https://jira.atlassian.com/browse/JSD-1736 seemed to be a decent answer, however, I'm not sure it completely fits the bill and in my original support request, I was told, "The only way to achieve this option is if you were to edit your Service Desk's permissions and remove the 'Create Issue' permission from all groups/users except for the 'Service Desk Customer - Portal Access'. This will remove the Service Desk project from the Create button in JIRA but will also require users have a separate Customer Portal only account set up to create issues. I understand that this will fine for customers only that shouldn't have access to JIRA but can cause issues if the user is a JIRA user that can access other projects. The only resolution to that issue at this time is to have two separate logins for that user, a general JIRA login when they need to create/work on issues in JIRA and a separate Customer Portal login when they're required to create a new Service Desk project."

sworley1283103287 Have a look at a related case for suggestions on how you can prevent use of the create button.

https://jira.atlassian.com/browse/JSD-1736

This is not the same as removing the button but may help to meet your needs.

Cheers!
Tim | Atlassian

Related issue: JST-189795: I need to be able to remove the "Create" button from the toolbar on the top of the window. The reason this needs to be removed is we need to eliminate admin team members from creating issues using that button. All issues needed to be created from the customer service desk portal site which outlines all the necessary required fields. Using the "Create" button bypasses those required fields. If removing the button is not an option, we need to at least like the URL to point to the customer service desk portal page to create issues. I have already had to slap admin users on the wrist to stop using that "stupid" create button.

While this isn't a complete work around you can do the following to prevent issues from being created within JIRA. This will force agents to create issues in the customer portal where JIRA Service Desk Permissions would apply.

• Remove create issues for the JIRA project permission from the service desk projects for JIRA Service Desk agents.
• Perform Convert existing issues to service desk request for existing issues.