Admin can face this issue due to GSTIN and PAN no. not updated in the Tenant.
Ask admin to update their Registration Number.
- Go to https://admin.microsoft.com/ > Billing Tab > Billing Account
- Click on Account Name
- Click on Edit Option and Add the Registration Number.
- After Enter the Registration Number save it.
- Now refresh the browser or ask admin to login into Incognito Window then try to accept link again.
- Check the Box then click on Accept & Authorize.
Note: Only Global Admin and Billing Admin can accept the link.
To change other information on your company's profile page:
- In the admin centre, go to the Settings > Org settings page.
- On the Organization profile tab, select Organization information.
- Update your organization's information, then select Save changes. Be sure to fill in all required fields marked with an * to enable saving your changes.