Now self-employed - What is the procedure to merge present Pension Certificate with Previous Pension Certificate?

I am have experience of more than 24 years. I started working to PVT companies since 1991 to 2000 for short periods. I got employment in MNC in Chennai and had an experience of around 11 years (from 2000 to 2011) and was not worked for two years. I withdrew the PF amount and received a Pension Certificate.
Again, I got an opportunity to work in MNC in Bangalore from Feb 2013 to Jan 2019 (around 5.8 years) and have resigned from the company due to health reasons.
I withdrew both PF account, but trying to apply for Pension Certificate. The pension scheme is compulsory for the service of more than 5 years.
The UAN for EPF was not introduced earlier and it was introduced in 2015 or later which is facilitated the employee to Online withdrawal of PF amount.
If I get another Pension Certificate, what is the procedure to merge this present Pension Certificate with Previous Pension Certificate.
I understand that I can avail Pension only after attaining 58 years. I 54 years old, and now self-employed.

You can get separate scheme certificate for separate block of services in different companies. Scheme certificate obtained for your first block of service, should have been surrendered with your second employer and like that. Since you have not done so, keep all scheme certificates received and receivable from EPFO and surrender the same to EPFO alongwith your application for monthly pension and few other documents, after attaining 58 years of age. Even you are at liberty to submit your documents now, but you will get a reduced amount of pension.