Simple rex works on REGEX101 but not in splunk.

[codedtech]

Hey so I have a list of of values, that need to be standardized. The values I'm need to transform look like this:
Pool1-dp
Pool2-dp
Pool3_MSDP
Pool4_MSDP
Pool5-dp

I need to trim the values to just have their proper pool names (Pool1). Here is the SPL
MySearch|rex mode=sed field="Field1" s/"(-dp)|(_MSDP)" but, when I run it in my instance I keep getting errors like this one.

Error in 'rex' command: Failed to initialize sed. Failed to parse the regex to replace.

I've spent about 4 hours trying to figure this out and I jut cant seem to do it. I wrote the REX in regex101, and it works there with no problem there. I did a bunch of googling and I tried most of the posts here at splunk answers, any help would be very appreciated.
Disclaimer I do not have access to the server where the instance is hosted, just the instance itself.

[richgalloway]

Your rex command may have been mangled by the forum (use backtics to prevent that), but it looks like the sed command is incomplete. There needs to be three delimiters: the first two enclose the expression to find and the second two enclose the replacement expression. Try this: rex mode=sed field="Field1" "s/(-dp)|(_MSDP)//".