How to change the database from sqlite3 to postgresql

i want to change the database of mayan edms from sqlite3 to postgresql

Some extra information is needed to answer properly:
Do you want to keep the data in sqlite3 or start from scratch?
Do you use the docker?

no I am not using Docker
and yes i want to keep the data in sqlite3 also

|In your config.yml the following should be present, where the ENGINE probably has django.db.backend.sqlite currently:

DATABASES:
default:
ENGINE: django.db.backends.postgresql
HOST: ***
NAME: ***
PASSWORD: ***
USER: ***

I guess starting a new virtual environment with the same mayan-edms version with the above database settings will create the proper postgresql DB.
Then you will need to migrate your data from sqlite3 to PostgreSQL somehow. Never done that though.

Maybe there are script someone here already created to do the job?

There is no config.yml file there is a base.py file is present

No … not in the source code. The config file is in your media folder:

.../media/config.yml

Before continuing you of course made some backups right?