Error while creating line items

[npastor]

Hi there, I've been trying to send some assignments to the canvas through lti 1.3 but I'm getting an error 422. 
After reading the Documentation i made this approach but I'm not sure what i'm doing wrong. 
I would appreciate if you could correct me, or redirect me to the correct documentation. 

MY REQUEST

Method: post

url:'https://wwnorton.instructure.com/api/lti/courses/:CourseId/line_items'

headers: 

Authorization: `Bearer ${a}`,

Accept: 'application/json',

'Content-Type': 'application/json',

Body (This body is going signed as JWT )

i tried couple of differents formats that I found on canvas doc, but without success, and then i formatted as IMS standard. 

 

[svickers2]

I assume your JSON body includes the closing array and JSON brackets (which are missing from the image I can see in your post).  The best I can suggest is that you ensure that your public key endpoint is accessible from the Canvas server, and try omitting the elements you are not using (text and resourceId) in case Canvas does not like empty values for these.

[npastor]

Thanks for your answer. 
Regarding the JSON brackets, yes they were missing in the image. 
Regarding my public key, i tried with a public endpoint and JSON key. 
Also, i tried omitting and filling in the elements that i was not using but i still got the same error 422 "Unable to process Entity" 
The point that is weird for me is if I send an empty array, or the Entity that i showed in the picture, or a simple entity (inside in array )I always get the same error. 

[svickers2]

If you're getting the same error with an empty array of content items, then try checking the JWT as a whole is properly formed (e.g. check headers).  Also try removing the sub and locale claims, adding a nonce claim, and passing the aud claim as a single-entry array.