scripting - What does mean in this part of the bash script?

Question

 payload="${payload/POS/$pos}"

Hello everyone, I'm working on a bash script and I could not understand the above part. I would be glad if you could help me. Have a nice weekend everyone

question from:https://stackoverflow.com/questions/65652348/what-does-mean-in-this-part-of-the-bash-script

Answer 1

Waitting for answers