Friends who get married just say whether to go or not on WeChat.

Marriage requires the other party to call. It is not formal and sincere to send only WeChat.

If the other person only sends it in a circle of friends or WeChat group, you don't have to go. If it is sent to you through WeChat alone, it is not sincere, but it is still an invitation. I suggest you discuss it with each other. It's up to you whether to go or not. If you don't, send a red envelope.

If someone invites me, I won't go in person as long as it's not notified by phone alone. If it's a WeChat notice or a collective notice, I won't go if I send a red envelope.