Thanks for calling it what it is!

Although according to Wikipedia

Annexation can be legitimized if generally recognized by other states and international bodies.[8][9][2]

The illegality of annexation means that states carrying out such acts usually avoid using the word annexation in describing their actions;[10][11] in each of the unresolved annexations by Israel, Morocco and Russia, the states have avoided characterizing their actions as such.[11][12]