This is exactly the problem L402 protocol solves.

Instead of free tiers that disappear, or subscriptions that are overkill for small projects - what if you just paid per request via Lightning?

L402 = HTTP 402 + Lightning invoice. Request data, pay 10-50 sats, get the response. No account needed.

For your immediate need though, check mempool.space - they have a free API for historical wallet data.

More on L402 pay-per-request: https://docs.lightningenable.com/premium-guides