Help Needed using apiconnector and bubble api

Hey all,
I’ve been stuck for around 4 hours on this, ive seen similar things in the forum but still cant work it

I’m trying to use apiconnector to access my bubble api

basically this is the line im using, and I have tried quite a few more[{“key”:“location”,“constraint_type”:“contains text”,%20"value":“available in truck”}]%26sort_field=ascending

ive also tried the same with all url text ie lots of %this and %thats

I also tried modifying the example on the bubble manual

I keep getting this

“statusCode”: 400,
“body”: {
“status”: “INVALID_DATA”,
“message”: “Issue with data for endpoint materialsrecords: [{“key”:“location”,“constraint_type”:“contains text”, “value”:“available in truck”}]&sort_field=ascending cannot be parsed as a JSON”

or when I substitute the constraints= for contraints%(number representing =)
I get a return of all the results instead of just the ones im looking for

It’s totally doing my head in.

so I can get the call working in postman[{"key"%3A"productnumber"%2C "constraint_type"%3A"equals"%2C "value"%3A"1408873-1"}]

however I recieve this in bubble

There was an issue setting up your call.

Raw response for the API
“{“statusCode”:400,“body”:{“status”:“INVALID_DATA”,“message”:“Issue with data for endpoint materialsrecords: [{\“key\”:\“productnumber\”,\n\“constraint_type\”:\“equals\”,\n\“value\”:\“1408873-1\”}]?private_key=a929a44a50f22d632c8abcc12e0ca4ba cannot be parsed as a JSON”}}”

I’m so frustrated.
I’m going to head to bed (Australia) and pray that someone can help me work this out