Hi Glenn,
Sorry for the delay answer.
I'm just a normal user of Excel. Mainly I solved myself what I wanted to do, or asked some professional. This time I got stuck. Nobody could help me.
I've checked what you sent me. I know this option. And I did it. This case I have to download every time the data, which is not makes easier my life then I visit the website every time.
I have an office 2019
This moment I download to my excel file the informations like this, and I refresh every time when I open it:

After I can use it with functions.
What I really need is, that I can read directly from the website the datas. The website is not constant. It is changing every day the €/HUF and USD/HUF rates.
So when I write a date to my Excel row, then I need the actual data from the mentioned website. Any kind of date, from the past also.
The websit:
https://www.mnb.hu/en/arfolyam-lekerdezes

After I select the currancies (€, USD), I got this:
https://www.mnb.hu/en/arfolyam-tablazat?deviza=rbCustom&devizaSelected=EUR&**datefrom=26%2F08%2F2023&datetill=26%2F09%2F2023**&order=1&customdeviza%5B%5D=EUR&customdeviza%5B%5D=USD

The dates are variable. So if I make it for a certain date in my excel, I can specify, what I need excatly:

Then I got:

Bingo, this is what I need.
https://www.mnb.hu/en/arfolyam-tablazat?deviza=rbCustom&devizaSelected=EUR&datefrom=**25%2F09%2F2023**&datetill=**25%2F09%2F2023**&order=1&customdeviza%5B%5D=**EUR**
So I specify my table the currency (EUR), the date (25%2F09%2F2023), then I can get the actual exchange rate. This moment I'm stuck to insert the date and the currency to the correct URL-address. As I know first I should convert the date to a normal text.
Logically I think it will work. Just too complicated.
I was thinking, there is an easier way to do the same: maybe a function, or an app which can do this job.
Sorry for the long description. I hope I was clear.