If this friend is your close friend and you are willing to attend their wedding, then you should not hesitate to attend. However, if you can't go for some reason, such as time or budget constraints, you should explain the reasons and express your best wishes to them.
In addition, if you don't communicate much with this friend in the WeChat group, or your own schedule doesn't allow you to attend the wedding, then you can choose not to go. Before deciding whether to go, you should consider your personal situation and feelings, and at the same time consider the importance of this friend's relationship with you.
Finally, whether you decide to go to the wedding or not, you should express your blessings and joy in the WeChat group, so that this friend can feel your care and support.