i loose my user fixtures in new shows

we have some LED par cans chinesse brand in our country and the library doesn´t have these fixtures loaded in.
so, i went to "built fixtures" and edit it from and existing fixture (the american dj LED par can) and works OK.
but when i load a new show the fixture is gone and i have to do all the process again
my question is... how do i keep any new fixture i create on the user fixtures option of the pacht menu? so if i made any new fixture, it apeear on any new show its loaded on the board.

thank a lot
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