I have many buys, different Cryptos (all purchased on Coinbase)

Does the IRS accept the Average Cost basis method for calculating cost basis?

For simplicity, if I know for example on Coinbase I deposited 20k ( across multiple deposits, just example) and maybe one purchase I have .1 BTC and another purchase month later .2. And another later purchase .35 etc etc.

But at the end of the day, altogether I have spent 20k and end up with 1BTC.

Can I use an average method to report to the IRS that my cost basis is 20k?

Then if I sell .5. For that .5 instead of calculating different transactions, I can report that cost basis for .5 is simply 20k?

Thank you in advance!