Thank you for trying Rename My TV Series, glad to hear you like it so for on KDE Neon.
As for your format question, you can define your own format string in "Settings", in the upper right corner under "Filename Format".
You can click the "Show Format Help" button to view details on how to build such a string, or click the button just before that (with the arrow down) to select one of the commonly used formats.
In you case, say you'd want: "My TV Show - S01E01 - Episode Title"
Then the string would be: %N - S%SZE%EZ - %T
%N = "My TV Show"
%SZ = Season number, with leading zero's (01)
%EZ = Episode number, with leading zero's (01)
$T = "Episode Title"
The "with leading zero's" depends on what the largest number is that, that is being used for a show.
So for example, if there are only 5 season, the season will be numbered; 1, 2, 3, 4, 5.
But if there are 10 season, the seasons will be numbered: 01, 02, 03, 04,... ,09, 10.
This works the same for episodes.
Since you may not know yet if this particular show lasts longer than 10 seasons, you can force seasons to be at least 2 digits, by checking the option "Season and Episode numbers at least 2 chars wide" or use %S2 instead of %SZ. %S2 forces a minimum width for a season number as well, but you can make it even %S3 etc. (up to 9).
Hope this helps.