Blockchain Explorer says received but it's not received yet!
That's not how Bitcoin works.
All computer-based wallets, including your friend's, have a copy of the blockchain (or have indirect access to a copy). If the blockchain includes your transaction, then the money has been received. All copies of the blockchain are eventually identical, only the last block or two might very occasionally differ for a short while.
Note that you can receive Bitcoin even if your wallet exists only as a secret number written on a piece of paper. The blockchain is the true record of what has been received.
If your friend says their wallet has not received the money there are at least three possibilities
- They are lying
- Their wallet has not got an up-to-date copy of the blockchain (i.e. is not "synchronised")
- You sent the money to the wrong address somehow.