Hello @Hamzariaz, Welcome to the Community 
I won’t say this as error. It is just an information that test tab is not having pm.test function to check whether the API request has passed your expected condition or not.
For example, I have two requests where I prefer one request to pass 200 response and the other to just have some code store and get cookies. The pm.test show the pass status, but the other one without any pm.test that shows The request does not have any tests. PFA, the attached screenshot for reference.
Edit 2:
To run the request parallelly, I will suggest using Postman’s CLI tool Newman.
https://learning.postman.com/docs/running-collections/using-newman-cli/command-line-integration-with-newman/#getting-started
Reference:
I hope this is helpful 