If you see “(32-bit)” and you are running { -brand-name-firefox } 56.0 or older, updating to the latest { -brand-name-firefox } version should automatically upgrade you to 64-bit.
Ma twalaḍ "(32-bit)" ticki tesselkameḍ { -brand-name-firefox } 56.0 neɣ aqbur, asader n lqem aneggaru n { -brand-name-firefox } ad k-yessali s wudem awurman ɣer 64-ibiten.