The problem. It's not on a wallet. Lets say the website is called marketplace.com. I bought some stuff from marketplace.com and paid $14,000. Well, they dont ship to USA so they refunded it. All I have is the private key. There is not built-in app on that website. There is no wallet. There is no interface. All I literally have is a bitcoin address.
When I try to do what you say, it doesn't let me type in an address. I can request a payment from someone, but still that requires them to have a wallet and send money to me. All I have in a private key. Nothing else.
Please do not make a duplicate thread. I saw that you made one in beginners and help with some more info.
From your other thread, you say you have tried:
I have used all of the above.
This is how you sweep Bitcoin from that private key you have into Electrum. I guarantee this will work if you actually have a legitimate private key (It should start with a 5, K or L and be either 51 or 52 characters long) and are actually using Electrum. Sweeping will move the Bitcoin from that private key to one in the Electrum wallet.
Open Electrum. Make a new standard wallet if you haven't already. Once the wallet is ready, go to Wallet > Private Keys > Sweep. There will be a big box that is labeled "Enter private keys". Enter in that box your private key. The address in the box below is the address that the wallet will send the Bitcoin to automatically. Click Sweep and it will move the Bitcoin from that private key to your wallet.