Cloudflare Api token & limits

Hello,

We are using the Global Api Key of an admin account (a seperated member/account from the default company’s, Super Administrator) in order to purge cache from our side programmatically, following the CF documentation.
We need to give limited access/permissions to the seperated account only for cache purging.
After trying to use Custom Api Token instead of Global Api we get a failure.
Can we use the Custom APi Token instead of Global Api and how? Otherwise, how can we use the Custom Api Token we have already created in order to give the appropriate limited access/permissions to the account?
Is there any conflict with the Plans? We are on PRO Plan. Do we need Enterprise edition in order to have these specific permissions? Could you help us?

I’m using CF API Token fine on a CF account (free plan) for my CF purge script just requiring Zone.Cache Purge permission which has invited admin access to another CF account (enterprise plan) for which the zones are.