Actually wikipedia says

"It is divided into Upper and Lower Polog. Tetovo and Gostivar are the largest populated towns in this valley and Albanians form an ethnic majority in the region."

anyway, there are many theories about Kastrioti's roots, as long as there was not Albanian identity. I personaly think he had mixed Slavic and native roots.

where is this desert in 1:43?

He is regarded as Albanian by the official History I believe. But considering his family connections all are Slavic. Just have a look of any of his relations "Jelena, Stanisha" some are typical Slavic and some Church Christian Names.  Personally I don't care if he was Albanian or Slav as much as I don't care if Alexander was Greek or Macedonian. For me it is not a big deal, But if some are making of that a great deal I accept the challenge.

Regarding the desert it could be vicinity of Prilep.

Hike up Markovi Kuli