Help canceling BTC Pending Transactions

Please I need help to cancel two BTC transfer transaction that have been pending for over a week now. As per my research, I need to transfer back to myself but I can’t find the nonce option to do that… Help me with canceling it Please.

BTC tx can be reverted if confirmed. Also, if not confirmed, but made without Replace by fee enable function, then only option is to install a full bitcoin wallet for PC and use a UTXO doublespend feature, but, this is not a easy process, and to do so, you will need to spend much more on tx fee.

Btc tx cant(!) be reverted, mispelling in first message. Be very very careful if you use bitcoin network. Also bitcoin network dont have nonces.

If I intall on PC, will I need to input the recovery phrases?. Or I will have other alternatives to login?
Asking because I don’t remember it.