Swagger error : Parameter (Accept) is not an allowable value (application/json): */*

Hi,

I am testing an IFTTT API using Swagger (see YAML below)

and I get the below error when I test it: 

Error: Parameter (Accept) is not an allowable value (application/json): text/html

I just can't get my head around it. The parameters are :

Any idea? Thanks a lot.