Hello @Eng Hooi Sun
Thank you for reaching out. I would like to confirm below details with you:
- External users with Global Admin/Reader role should be able to access MyApps portal using direct link as using following syntax: https://myapps.microsoft.com?tenantid=yourdomain.onmicrosoft.com.
- The external user having Global Admin/Reader role would only be able to view the apps assigned to their user identity in specified tenant and not all apps would be visible. This access limitation for external identities on myapps portal is expected and bydesign.
- Also, for this to be available your tenant user settings for Enterprise Applications should have following conditional set to yes: "Users can add gallery apps to My Apps".
- Additionally, Guest users with Global Admin/Reader role should be able to access https://portal.azure.com and browse all the Enterprise Applications as well as App Registrations.
- Also, your external collaboration setting for users should set to most inclusive for this to work.
I hope this answer helps to resolve your issue. Please "Accept the answer" if the information helped you. This will help us and others in the community as well.