Not that it's completely reliable, but Wikipedia also has information which matches the article (https://en.wikipedia.org/wiki/Homelessness_in_Finland), no discussion on the talk page, and no signs of an edit war in the history.
I tend to think of the homeless as sleeping in bags or on cardboard in cities, trying to get money for whatever it is they need. I really saw the true meaning of homelessness when I was in Austin.
The Y-Foundation exists https://ysaatio.fi/en/home and they have reports too.
> apparently we don't have homeless problem so we don't even keep an official record
There is an official record by the Housing Finance and Development Center of Finland: https://www.ara.fi/en-US/Materials/Homelessness_reports
More information can also be found at https://housingfirsteurope.eu/countries/finland/