If you are trying to load a wallet, then you do not need to be using a wallet specific endpoint.
loadwallet is not actually a wallet RPC so it does not need the wallet specific endpoint.
If you are trying to access a wallet that has already been loaded, then you have the wrong endpoint. The endpoint does not include the wallet.dat file. Bitcoin Core gives wallets names based on the directory that contains the wallet.dat file, and when it creates wallets, it puts them in directories of the name that was provided. The wallet RPC endpoints work similarly - they use just the wallet name. So the URL to access a particular wallet should actually be
Note that this URL does not have a trailing slash (
/). If you have a trailing slash, then Bitcoin Core will incorrectly determine the wallet name to be
another_wallet/ where it is actually