Hey. I just made this. It's a coincidence that the OP and me are building it at ...

Hey. I just made this. It's a coincidence that the OP and me are building it at the same time, but AFAICT the OP service does not support recurring tasks, but Pocketwatch does. Per your example, try:

   curl https://api.pocketwatch.xyz/v1/timer/new \
   -H "Content-type: application/json" \
   -d '{ "apiKey"             : "i_am_hn_and_proud" 
       , "url"                : "https://host.tld/?my_param=my_val" 
       , "method"             : "POST"
       , "interval_unit_type" : "second" 
       , "interval_unit_count": 1 
       , "duration_unit_type" : "minute" 
       , "duration_unit_count": 6 }'

You can use curl but the Node.js client library[1] is probably easier. I've made a free demo API key for HN readers that should be enough to let everyone try it out a bit[2].

[1] https://www.npmjs.com/package/%40dosy%2Fpocketwatch [2] https://news.ycombinator.com/item?id=17353486