how to update a chart automatically if news lines will be added

I am so confused by a problem that I can't resolve, In fact, I have recorded a Macro that allows me to generate a chart in my table, but when my table updates, for example, I have some news lines, I can't get the updating in the chart, how should I change the VBA code so that this function could be realized.

Just another question, would it be possible to obtain the equation of the curve that I traced by VBA, I would like to calculate some other x for example.

Just an excel table for you to understand my question

Thanks a lot for your help, I really appreciate it.