We bought crowd to synchronize AAD accounts for JIRA Service Desk.
We have 1000 customers， but only 50 can login JIRA Service Desk, so the pricing count should be 1000 or 50?
Now I can't login crowd as admin, it shows account amount over limited.
Crowd's license counts any user object that exists in Crowd, regardless of if they have application access (so it doesn't matter that 1000 people are JSD Customers, Crowd needs to be licensed for 1000 users, not just your 50 x JSD Agents).
Sounds like you'll need to revise your Crowd license and move to 1000+ users
If you want to just get in temporarily and adjust your AAD scoping, you should be able to get a Crowd DC trial license, just make sure you've got your current license handy as you'll need that to revert back once the Crowd user count is lower than your purchased license.