I read this another forum:
Send another BTC from your wallet but this time chose TX with the high fee!
and miner will confirm your both TX
Is it true for blockchain?
That will only work if the new transaction is spending the same UTXO as the parent (previous) unconfirmed transaction.
As miners need to mine the first transaction to get the extraordinary high fees from the second one that will make up for it.
If the fees are high enough, then yes, this will work and is also called a CPFP (Child-Pays-For-Parent)