Adding lines via plugin

Dear musescore coders,

I'would like to add lines in my score via plugin. Trying a lot with Textlines and Textline.Segments won't give me the correct result of a simple line from tick a to tick b. How do I have to code this this the right way?

An additional question would be, how to adress different types of lines. Adding a simple line in the lines pallet returns another line than adding a Note Anchored Textline.

Thank you for your any help.

Kind regards,
music_maker