If Kiara was the cub at the end of the film and Kopa existed, then Kopa would be born during Scar's reign.

Kopa is non-canon. He's from a set of spin-off comic books called The Lion King: Six New Adventures.

The presentation ceremonies are drastically different.

Kiara being the lion cub at the end of the first movie makes more sense to me as she is the only daughter of Simba and Nala in The Lion King 2.

i saw his eyes and it is kopa

It's Fluffy by the creators of TLK commentary shown in the 2004 DVD. They stated "here's Fluffy, Simba and Nala's cub. Let's just end it at Fluffy." During the production of TLK 2, Fluffy is redesign and becomes Kiara. Fluffy and Kiara are one cub. One of TLK 2 filmmakers stated "you think it's a king but it's a queen." My answer would be ether Fluffy or Kiara. Kopa is a character that only exists in the outsider books TLK 6 new adventures. He's not a Canon or a official character to the 2 films. Kion is only from the spin-off show The Lion Guard which is created by total different creators with a whole different storyline than the films itself. Fluffy still remains as Kiara. Since TLK and TLK 2 are combined together.

Kiara.

its a strange cub

Kopa.

or Kiara or Kopa