This will be the quickest, but most important tip you will ever get in your life when it comes to lifting weights in your life. In fact, it may just save your life. No schnitzel.
When lifting heavy weight, do not, I REPEAT, DO NOT attempt to lift without a spotter! It is irresponsible and can result in serious injury or quite possibly lose of life. I had a friend once that thought he did not have to follow the rules of lifting, decide he was going to do chest presses without a spotter. He also was attempting heavier weight than normal, without a spotter. He ended up pinned on the bench under the bar until someone came along and unpinned him. Fortunately he only suffered minor muscle strains to his triceps and bruising on his chest. Don't be a Carl or Karen. Use a spotter. A caveat to that; use a spotter who can lift the same amount or more than you.
This concludes your safety brief on proper use of a spotter.