Flagship reactor

[Arshia_EB]

I bought this legendary reactor today but since my weapon was fully upgraded I couldn’t use it. But if I leave the weapon without upgrading, the game will be difficult for me.
So
I can’t use a good reactor and a good weapon at the same time.
because

and its my reactor and weapon

So, do you guys know what the solution is?

[Lunatico]

You need to buy its best reactor (Proton Chain Reactor), and upgrade the reactor.

[Arshia_EB]

thanks

[X676X]

Same to me