I have stamped the contract with the micro-signature electronic signature system, but if you directly use electronic signature in office, it will be a picture. What if someone changes it? With the help of micro-signature electronic fax system, they converted word files into pdf format on the Internet, which could not be modified after being stamped. Handwritten signatures are also acceptable, and mobile phones can be directly signed, which is quite convenient.

There are free, you can register directly on the website. You can also ask them for the locally installed version.