Having trouble prefilling multiple select field in miniExtensions form

[David_Nunn]

I need to open a record in a miniExtensions form prefilling values from Airtable fields - including a multi-select field.
I’ve used an extension to build a formula. The resulting URL works fine with an Airtable form, which populates all fields, including the multi select.
The miniExtension form won’t prefil the multi-select field using the same formula.
I can see the cause. The Airtable formula retrieves an array of values for the mini select field. However, it inserts a space after each comma.

Can anyone suggest how to adjust the formula to take out the spaces?

“Story form” &
“prefill_Idea%20Status=” & ENCODE_URL_COMPONENT({Idea Status} & “”) & “&” &
“prefill_Story%20title=” & ENCODE_URL_COMPONENT({Story title} & “”) & “&” &
“prefill_Magazine%20section=” & ENCODE_URL_COMPONENT({Magazine section} & “”) & “&” &
“prefill_Audiences2=” & ENCODE_URL_COMPONENT({Audiences2} & “”) & “&” &
“prefill_Magazine%20issue=” & ENCODE_URL_COMPONENT({Magazine issue} & “”) & “&” &
“prefill_Notes=” & ENCODE_URL_COMPONENT({Notes} & “”) & “&” &
“prefill_Task=” & ENCODE_URL_COMPONENT({Task} & “”) & “&” &
“prefill_Online%20platforms=” & ENCODE_URL_COMPONENT({Online platforms} & “”) & “&” &
“prefill_Newsletters=” & ENCODE_URL_COMPONENT({Newsletters} & “”) & “&” &
“prefill_Online%20pub%20date=” & ENCODE_URL_COMPONENT({Online pub date} & “”)

Any help would be greatly appreciated.

[David_Nunn]

I found that it is the URL encode function that inserts the space.
As a solution, I wrapped the URL encode function with Regex_replace to remove the space trailing the commas. The miniExtensions form now works fine.

REGEX_REPLACE(ENCODE_URL_COMPONENT({Audiences2} & “”),“%2C%20”,“%2C”)