how do i know which key has mined bitcoin? I mined some coin in 2019 - 2020 via Bitcoin Core which i know very little about.  I have used dumpwallet to get all the keys but there are hundreds ! how do i know which keys might contain the mined coin ?  Any hep would be great as ive been trying to sort this for over 12 months.
Thanks
You have to load the keys into software which can scan the blockchain and search for transactions that belong to them. The simplest way to do this is to just start Bitcoin Core and let it sync. During the syncing process, Bitcoin Core will also be scanning the blockchain for any transactions that belong to any wallets that are loaded, so once it is synced, you will see any transactions (and thus Bitcoin) that belong to you.