Flutter TCP SSL

Good evening everyone,
I’m new to flutter, I have a TCP server with SSL authentication created with node.js, I would like with Flutter to connect to TCP and send a string.
Can anyone help me? are the certificates .pem? because in node.js I have 3 certificates (client.key, client, crt, ca.crt).
In flutter do I use those same certificates or do I have to create new ones?
Anyone can give me a mini tutorial for the realization? I’m confused.
Thank you all in advance.
Best regards

Heyy @Andrea Check out this Stackoverflow thread, I think it will help you.