To convert a handwritten composition into text and send it to WeChat, you can use the following methods:

Manual input: Open the chat dialog box in WeChat, and then use your Use the mobile phone keyboard to manually enter the content of the composition. This may take some time and effort, but it ensures accurate conversion of handwriting into text.

Handwriting recognition software: If you have handwriting recognition software installed on your mobile phone, you can use the software to convert handwritten compositions into text. Open the handwriting recognition software, select handwriting input mode, and write your composition on the screen. The software will automatically convert your handwriting into text, which you can then copy and paste into WeChat to send.

Third-party applications: There are third-party applications designed specifically to convert handwriting into text. You can search for and download these apps in the app store, such as "Handwriting Input" or "Handwriting Recognition". Install and open the app, then follow the app's instructions to handwrite your composition. The app will automatically convert the handwriting into text, which you can then copy and paste into WeChat to send.

Please note that using handwriting recognition software or third-party applications may require some getting used to and adjusting to ensure accuracy. In addition, since the interface and operation of each application may be different, please follow the guidance of the specific application.