See this previous discussion. Passing emoji strings from files into text() is almost certainly not going to work.
You can attempt to integrate Java emoji solutions, just be aware that they may not work either on Java 8 – check the minimum Java requirements of a solution.
https://developers.redhat.com/blog/2019/08/16/manipulating-emojis-in-java-or-what-is-🐻-1/
None of this speaks to g4p integration – just the basics of trying to get an emoji character saved in a string to display in Processing.