How to run two methods in parallel

I am using Codeigniter 4.2. How to run two methods each containing loop to import the data from excel to the database. basically while importing the data, I would also want to show the progress bar. but in my case, once the importing of data is completed, the progress bar shows. when I look at the spark server, it is waiting for the first request to get completed. I am not sure whether this is the limitation of the spark server or some other issue. I have tried multiple options but nothing is working. Please help with this with a sample code to run the two requests in parallel. I have been working on this for 3 days. Please consider this a high priority.

Regards,

Ramesh Marimuthu