@Kanravee Warinsirikul Thank you for reaching out to us, If you have already submitted a request to list an app in the gallery and the request is still waiting for a Microsoft review, you can apply to become a Microsoft partner later. You do not need to register as a Microsoft partner before submitting the request.
However, if your request is not approved and you want to resubmit it, you will need to register as a Microsoft partner before submitting the new request. This is because the Microsoft Partner Network is a requirement for listing apps in the gallery.
To register as a Microsoft partner, you can visit the Microsoft Partner Network website and follow the instructions to sign up. Once you have registered, you can resubmit your request to list the app in the gallery using your Microsoft Partner Network email address.
Keep in mind that becoming a Microsoft partner may take some time and there may be additional requirements that you need to meet. You should review the Microsoft Partner Network requirements and guidelines to ensure that you are eligible to become a partner and to understand the benefits and responsibilities of being a partner.
Reference: Submit a request to publish your application in Microsoft Entra application gallery
Let me know if you have any further questions, feel free to post back.
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