There are some sites where you can check the balance of multiple addresses how about this one below
- https://awebanalysis.com/en/bitcoin-multiple-address-check-balance/

Or if you preferred API calls then blochchain.info still has some API calls that you can use for checking multiple addresses.

Read the answer from this post below
- https://bitcoin.stackexchange.com/questions/62018/blockchain-info-multi-address-lookup