Run time complexity for inserting a node in the Linked List at the end

Hello Everyone,

In the Data Structure Course for Linked List topic there is one mistake on “2-What are linked list (4:22)” video at 1:55 time stamp.

For the Linked List if we want to insert the node at the end then run time complexity would be O(n) as we need to create a node O(1) then referencing tail to new created node O(1) then finding last node O(n) then referencing that last node to newly created node O(1) so >> O(1) + O(1) + O(n) + O(1) = O(n).

Can anyone please correct me if I am wrong?

Thank you.