Ansible parse file and read into variables

Question

I have a file I have to read from, that is written like this: (it cannot be changed)

user_passwords:
- { username: user1, plaintextPassword: password }
- { username: user2, plaintextPassword: password }

I need to read the file, then assign the values above to the following variables and write them to a file.
I'm not sure how to loop through this in ansible.

Variables and values I need to write: user1: user1 user1password: password user2: user2 user2password: password

Here is what I've tried:

- name: Read file 
  include_vars:
     file: myfile
     
- name: assign variables 
    user1:  {{ username.1 }}
    user1password {{ plaintextPassword.1 }}
    user2:  {{ username.2 }}
    user2password:  {{ plaintextPassword.2 }}
  loop:  user_passwords

but this is not giving me any results. Does anyone have any ideas?