Easy solution is to use CoingGecko cand create account there, but there is also alternative apps and I suggest trying one app called crypTrax from bitcointalk member Escaflowne.
This open source app works on all operating systems and you don't have to create any coingecko account:
https://bitcointalk.org/index.php?topic=5375431.0
github: https://github.com/Escaflownevan/crypTrax

One more alternative option for desktop portfolio manager is open source app called Rotki:
https://rotki.com/

Do your own research before using and installing anything.