Correctly identifying sets in tennis

[Dallas]

Could you please advise on the custom column solution? Seems that it would be the best for me at this moment.

This page of the user guide explains how to make a custom column, for what you've asked for you just need to set it to the fixed price you want /(and choose if its a back or lay bet that is to be placed
https://www.betangel.com/user-guide/custom_columns.html

Ok, this seem to work with one-click interface. But my aim is to have it in the guarding column list as in the image. Tried to play with it but not sure if it is possible to do it using guardian custom column.

The Guardian custom columns are only for displaying market/selection information
The custom column on the one-click screen can be used for placing manual bets, starting/stopping servants and displaying market/selection information