Change to simpler regex notice the
" at the end:
- Your Regular Expression Extractor scope is not correct, you should be extracting the value from the document Body
- You need to escape this
PaymentIDas question mark is a meta character and it must be escaped unless it is in group or in class
If you're not too comfortable with regular expressions you could go for Boundary Extractor instead, in particular this case it would be much easier.