linkedin - 'Create a Campaign Conversion' linkedin API giving 'is not a Compound key' error with status 400

Question

I am new to using linkedin APIs and all I am trying to do is use this API to create a campaign conversion, by making a PUT request through this API https://api.linkedin.com/v2/campaignConversions/(campaign:urn%3Ali%3AsponsoredCampaign%3A337643194,conversion:urn%3Alla%3AllaPartnerConversion%3A70203)

However, I receive an error of the form 'is not a compound key' with status 400. Any ideas on how to resolve it?

Linking official docs below for reference--

https://docs.microsoft.com/en-us/linkedin/marketing/integrations/ads-reporting/conversion-tracking?tabs=https#create-a-campaign-conversion