Perhaps you need to buy a membership.
Just like on chess.com.
Their site says there are some free lessons but access to the rest requires a Gold Chess kid membership.
They also have a support group- https://support.chesskid.com/article/339-contact-us
I watched all 6 video lessons on the pawn level and my status reads 100%, but still will not allow me to watch lesson 7. Please advise.