UNABLE TO Add Seeed boards to Arduino IDE

Hi at all, my name’s Simone I from Italy.
Recently I buy an Seeeduino V4.2 board.
When try to Add Seeed boards to Arduino IDE on the PC in my home following this steps:

arduino IDE (2.1.0) return the folliwing ERROR:

Some indexes could not be updated. Get “https://raw.githubusercontent.com/Seeed-Studio/Seeed_Platform/master/package_legacy_seeeduino_boards_index.json”: dial tcp connectex: Impossibile stabilire la connessione. Rifiuto persistente del computer di destinazione.: https://raw.githubusercontent.com/Seeed-Studio/Seeed_Platform/master/package_legacy_seeeduino_boards_index.json

Instead I tried on PC in my office I had no problem.
Can someone help me?

Issue was solved by modifying HOSTS Win10 file.
There was (don’t know why) an entry like this: raw.githubusercontent.com
I deleted it and now it works.