First of all, thank you very much for all your replies.
I couldn’t figure how wrong I was in my interpretation.
As I see my interpretation of the term “validation” differed from the one you all had described, I searched what it means from a psychological point of view.

I came across to three interesting articles about the topic.

The power of validation

The Power of Validation | Psychology Today

Why validation matters

Why Validation Matters: Insights from 5 Just-Published Studies | Psychology Today

Levels of validation

Easing Partner Pain: Six Levels of Validation | Psychology Today

It seems that it’s kind of support by hearing, compassion and understanding the feelings and actions by a person, according to the circumstances that take place in an event that person is going through. It has nothing to do with agreement or disagreement as I used to think.

Mea culpa, because I thought it was said in the sense of being agree or having approval.

Anyhow, I don’t consider a site like this the most appropriate to give validation in a deep level since we barely know people’s real circumstances. As much we can give some kind of support and hear the person while going through similar experiences.
To validate someone, again, in a deep and effective way, there are phycs, relatives, friends, SO.s as the right ones. I’m not dismissing online contacts but there has to be a big knowledge between them and know that the way the person lives the situation is close the a real picture.

But, this is only my personal opinion. As I understand that term support has a larger extent than the one is admitted here.

Thank you again all for your clarification. 😀👍