AI software has the following methods to fill in the trademark R:

1. In the English input method state, press and hold Alt+0174 and then release the Alt key to type.

2. Download Sogou Input Method and find ? in Sogou Input Method - Special Symbols.

3. You can type an "R", draw a circle outside and draw it up.

4. Type the trademark in Word, copy the symbol from Word to AI, and then convert it to music.

5. Download the vector image of the trademark "R" from the Internet and insert it into the file.

The above is how AI software fills in the trademark R.