About reflective grammatical form hitpael in the Hebrew word for "praying" and in Ve-Hitmakartem

If according to Ramban, the second exile is hinted in the rebuke of KiTavo, when was the verse (Devarim 28:68): וְהִתְמַכַּרְתֶּם שָׁם לְאֹיְבֶיךָ לַעֲבָדִים וְלִשְׁפָחוֹת וְאֵין קֹנֶה fulfilled?
This video is largely based on an article by Mitchell First seforimblog.com/2016/08/the-m...