To the Cargo Platform is a quest in Chapter 6, "Light the Way", in Final Fantasy VII Remake, taking place in the Sector 4 Plate. After reaching Section H of the Sector 4 Plate Interior, Cloud Strife, Barret Wallace, and Tifa Lockhart look for a way to disable the sun lamps in order to secure enough power for the platform and progress to Mako Reactor 5.
Once the cargo platform is activated, walk onto it and use the switch on the side. Barret will ask Cloud if he wishes to return for some materia, referring to the "Collapsed Passageway" sidequest to obtain the elemental materia; if the player has this, he can be ignored, otherwise it is worth obtaining the materia.
After moving the cargo platform along to another platform, the catwalk on the right leads to an area where Sentry Rays, Sentry Gun Prototypes, and Sentry Launchers are fought. If the player has an elemental materia, it can be paired with the Lightning Materia on Tifa to allow her to do significant melee damage, taking advantage of her high Attack Power attribute. Cloud and Barret should have healing spells, with damaging Magic Materia on Cloud also being very useful. The party should finally heal their HP and MP beforehand.
Once ready, engage the enemy. Of the enemies, the Sentry Launchers are the biggest threat, and the only ones Cloud and Tifa can destroy. Barret can quickly take out the Sentry Rays, allowing Cloud and Tifa to focus on the Sentry Launchers, making sure to dodge their attacks frequently. Once they are eliminated, Barret can destroy the remaining Sentry Gun Prototypes, and Cloud or Tifa can use spells against them.
Once all are defeated, use the ladder to a small vent, head inside, then take the ladder up, and take the moogle medal from the treasure chest on the right. Proceed left, then left again up some steps, and follow the linear path to the final point, where a cutscene commences. After this, the next quest, "Reach Mako Storage", begins in the following chapter, "A Trap Is Sprung".
Hard mode tips
As the final big challenge for the chapter, it is viable to unload more powerful spells against the enemies. Equipping Steadfast Block Materia is especially helpful for durability, and Barrier Materia can also be useful for durability. Barret should use Lifesaver, and it is crucial that he equip a ranged weapon. Maximum Fury can be useful for destroying the turrets, while Cloud and Tifa defeat the Sentry Launchers first.