NEWBIE: how to use the this .csv with the WP Newsletter plugin?

Hello,

I’m sure that this question is very idiot, but…
How can I use the .csv file exported from Coming Soon & Maintenance Plugin with your Newsletter plug-in?

I want to announce that my website will be online soon so…
Can you help me in this task? ^__^

The .csv file content is something like this:

——————————————————–
ID,Date,Email,Firstname,Lastname,Fullname
0,”2019-06-08 10:34:04″,[email protected],,,
1,”2019-06-12 14:28:22″,[email protected],,,
2,”2019-06-14 13:02:37″,[email protected],,,
——————————————————–

Thank you! (^___^)