RG and Google Scholar use different datasets for their h-index calculation, that's why providing an h-index without its source is worthless even when you want to use it at all.

For more details, refer to Wolfgang Dick's answer to this recent question:

https://www.researchgate.net/post/What_is_my_H-Index

Ok, can you, please, explain to me why I see h-index = 2 but I don't see it in my articles?

What do you mean by "I don't see it in my articles"? The h-index refers to you as an author, not to individual articles.

I mean that one article was cited 3 times and another one time. Which articles were cited to get h-index = 2?

Look here to see the difference

https://scholar.google.com/citations?user=5rOU2IwAAAAJ&hl=uk

Dear Sergii Lysenko You are right something mysterious is going on here. It has as indicated by Jürgen Weippert nothing to do with Google Scholar (differences between GS and RG are ‘normal’). But the ‘problem’ is that your stats indicate 5 citations while I only count three:

Article Evolution of digital transformations in IT companies

Article Digital technologies in personnel management

In RG the h-index should be 1 (just like in GS in this case).

Best regards.

PS. Did you merge two paers or is one of your papers no longer in your profile that might explain the disappearance of 2 citations?

Thank you for helping and understanding.

Here is a fairly detailed definition of the h-index: https://libguides.graduateinstitute.ch/metrics/author_impact

Thank you