Pinduoduo can't find anyone by SMS.

If you send a friend message, the other party can't see it, which may be due to the network. If the merchant doesn't hear from you, it may be that the other party has blacked you out. I suggest you check to see if everyone can't receive your message. If only one good friend can't hear from you, it's the other person who has blacked you out. If all your friends can't hear from you, it may be that your account has been blocked from chatting with friends.