Le SKR 1.3 utilise des processeurs ARM processor, so you cannot use Arduino IDE anymore.
Download and install this Visual Code IDE.
You will need this program to modify and create firmware file for your SKR board.
https://github.com/bigtreetech/BIGTREETECH-SKR-V1.3/tree/master/BTT%20SKR%20V1.3
https://www.hta3d.com/en/blog/how-to-connect-the-skr-v1.3-board