Calculate sample size from margin of error and confidence level

I need to calculate the sample size for the data I have. I am given a margin of error5% with a confidence level 95% .

Which formula can I use to get the sample size value if the total population size is X? Sorry, I searched the internet but couldn't find a formula for this purpose.

https://www.statisticshowto.com/probability-and-statistics/find-sample-size/#Cochran

Any help is appreciated.