How can I hide my bitcoin transactions to protect anonymity from others? Please take a look at this transaction link of bitcoin :
https://www.blockchain.com/btc/tx/blablablabla

My bitcoin address is :  blablablabla
You can see all of my transactions by this link :
https://www.blockchain.com/btc/address/blablablabla

My friend address is :  bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz
But you can't see all of his transactions by this link :
https://www.blockchain.com/btc/address/bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz

What is this address : bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz
And why is it undetectable?
How can i hide my transactions from others like that address?
Your address is a classical 1 (Pay-to-public-key-hash) address. Your friend has a newer Bech32 Pay-to-Witness-public-key-hash-type address. The block explorer you referenced is partially compatible with Bech32. Sometimes, it doesn't work. On the other hand, there's nothing that prevents you from looking at your friend's transactions using a different block explorer such as https://Blockstream.info or https://blockchair.com/.