You can directly ask for the other party’s contact information during chat.

Only with the consent of the other party can the contact information be given to you, otherwise there is no other way to obtain the contact information.

If you are a boy, there are actually many ways to get in touch, but it mainly depends on the relationship between the other person and you. If you have just started to get to know each other, and if the conditions are not very favorable, then Don’t be too anxious. Establish two or three meetings and exchanges first. Then find a suitable topic and say, let’s add WeChat. We can communicate about anything in the future. Or find a topic that is her expertise, or find a topic that is your expertise. Just add a WeChat message and say that if there is anything you want to know in the future, please ask for leave. If it is not clear that the other party has a good impression of you, do not show too obvious purpose, such as the price, WeChat will invite you to dinner or have a date in the future. It's not a good idea to go out together, watch movies, etc., and you'll probably be rejected.