Memos or anyone who chats on WeChat must have a third-party input method (because Apple's own input method has no line feed function).

Then in the memo, enter any characters, such as:

1 line break

Double feed

3 newline character

4 newline character

And so on.

Finally, select all, copy 1-4 vertically, paste it into the WeChat signature, and delete the numbers.

I just tried, and the method is feasible. Here's the thing.

Shall I type out the phone memo, wrap it up and post it on the last line? Six symbols in parentheses, and then copy and paste them into the personalized signature.