There is extension with manifest v3. It works in developer mode on Opera and Chrome. But when I try to upload it to addons.opera.com, occurs error:

manifest.json is invalid. Please correct it and try uploading again. The parser reported: {'resources': ['/script/domain/player.js'], 'matches': ['https://music.yandex.ru/*'], 'extension_ids': []} is not of type 'string'

You can see that in message uses ', but in file all of it is "

{"resources": ["/script/domain/player.js"],
"matches": ["https://music.yandex.ru/*"],
"extension_ids": []}

Whats problem?