To receive bitcoin all you need to do is share one of the addresses in your wallet with the person who wants to pay you. With the receive tab Electrum tries to create a workflow for receiving bitcoin that incorporates adding a label to your address, an expected amount and saving all this in the wallet as a receive request. The fact of the matter is non of this is strictly necessary. As mentioned before, all you need to do is share any one of the addresses in your wallet with the sender. But it does help you organize things if you also label your address etc. and save the whole request in your wallet.

The label and amount you set in the receive tab are only for your own reference. They are not shared with anyone and they don’t restrict how much bitcoin someone can send you.

So here’s how to use the receive tab in electrum:

• Switch to the “Receive” tab
• Enter a description in the “Description” field.  This is not shared with anyone and is only for your own reference. When you receive money this description will show up on the history tab.
• Enter an amount, if you like, in the “Requested Amount”. Remember this does not change how much bitcoin someone can send you and is only for your own reference.
• Set request expires to never or leave it unchanged. This option doesn’t do anything meaningful for on-chain transactions (i.e. not Lightning). People can always send you bitcoin and addresses don’t expire.
• Click on Request
• Switch to the Address tab on the right part of the receive tab. Click on the little blue icon to copy the address to the clipboard or scan the QR code. Communicate this address to the sender.
• At the bottom of the screen under “Incoming Payments” you can see past saved requests. Clicking on one should populate the address tab. You can also right click a request to copy other things like the description.
• When you receive money it’ll show up on the history tab.

So that’s the Electrum Receive tab. As you can see it’s designed to hand out new addresses each time you need one. This is because address re-use is a bad idea. That is not to say you can’t do it. It’s just not recommended.