How to add a slack variable in a optimal problem?

In this question, https://math.stackexchange.com/questions/3159910/can-we-get-optimal-values-when-we-calculate-the-optimal-problem-every-time ,someone suggests me to add a slack variable to analyze what is causing infeasibility . How do i add it ? Can anyone teach me or give me an example? Can i just assume F_k become a slack variable?because the constraint has already told me F_k is greater and equal than 0

You have been interacting with Johan Lofberg at the link you provided. Read his article https://yalmip.github.io/debugginginfeasible/, including section 6. “Solve a model with slacked constraints”

There are examples at Can someone please help me with my QP problem? and QP problem infeasible .