I am not running anything with contaminated oil that could have been a typo.
I thought that you
1) drained the crankcase for an oil change
2) Accidentally filled the crankcase with HYD fluid
3) Then you re-filled the crankcase with motor oil
4) Stopped to ask advice here
So, if the timeline is right, you have a crankcase with motor oil and an unknown quantity of HYD fluid it. In other words, contaminated.
My plan is to run the Gen for 15 min with the new oil change then drain and replace with new oil and then run for a 30 min then put new oil once again hope that will work. I will let you know
So if I read this right, you are going to run the contaminated oil 15 min, drain, refill, run for 30 min, drain and refill with the 'final' oil that will remain until next change.
OK.... so now the contaminated oil will be run, and an additional oil change will be added.
Some here proposed that you drain this oil, and put in new. Sure, there will technically be *some* HYD fluid in there forever, but the meaningful majority will exit with the 'first refill' oil being drained IMO.
But the prevailing advice seems to be 'RUN IT' with the contaminated oil, and assume there will be cleaning benefits from doing so. Then after running, drain the contaminated oil and refill with clean oil.

different strokes, different folks.
Honestly, We cant hear your generator from here, so if the cleaning idea runs afoul, no problem! Heck, back in the days of sawdust quieting a rear end, and oatmeal fixing a radiator leak, people would add all sorts of stuff to 'deep clean' their engine. Some still do! And empirical evidence supports they are right. Being that there probably hasnt been any progress in oil technology or engine manufacturing in the past 40 years, you should be fine using the tricks of yesteryear, right?
My money is betting you will be fine either way. I genuinely wish you the best of results, regardless of method. Those gensets are pricey.