API Key for account

Topic: API Key for account

We have 20+ client accounts. For one of the client account we need to assist with api integration for dispatch system. anyone can assist and guide us regarding the same.
- Do we need API Key for that client account to limit the scope of the call ? if Yes ...who will provide the API Key for the client account.
- So far chat support was not able to assist on the same

Thanks & Regards