Need to use the incoming variable in the bitbucket pipeline

[Mohit Gupta]

I am trying to trigger the Bitbucket pipeline from the REST API. I am using the reference link as https://developer.atlassian.com/bitbucket/api/2/reference/resource/repositories/%7Bworkspace%7D/%7Brepo_slug%7D/pipelines/

At this link there is a sub-heading called Trigger a custom pipeline with variables

In this, we are passing the variables in the JSON body.

My question is how can I use the variable I am sending from the JSON body in the Bitbucket pipeline?