1) In the name of your company, briefly explain the reasons for coming to China and the invited party's name, passport number, date of birth and other information in English or English/Chinese, and affix the official seal/signature ... The format is the same as that of ordinary fax letters, generally indicating that the recipient is the visa office of the local China Consulate.
2) Fax the invitation letter to the other party (some countries need the original express delivery), and then apply for a visa at the local consulate in China. If their stay is not long, they only need to apply for a 30-day tourist visa. If it is a fairly formal visit, foreigners can be advised to apply for a business or visit visa in the local area (generally 90 days). (transfer)
If you haven't dealt with him, he directly asks you for it, so it's better not to give it, because if you invite him, you must ensure his behavior in China. Besides, there are many scammers using this technique on the Internet.
Personal opinion, for reference only.