Iron Golem — ruling 1

If the Iron Golem can't attack or block for any reason (such as being tapped), then it doesn't attack or block. If there's a cost associated with having it attack or block, its controller isn't forced to pay that cost, so it doesn't have to attack or block in that case either.

Iron Golem : règles, fonctionnement et interactions (MTG)

Iron Golem is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Vigilance This creature attacks or blocks each combat if able.

How it works : Iron Golem

Original English text — Wizards of the Coast / Scryfall

#1July 23, 2021· Wizards of the Coast
If the Iron Golem can't attack or block for any reason (such as being tapped), then it doesn't attack or block. If there's a cost associated with having it attack or block, its controller isn't forced to pay that cost, so it doesn't have to attack or block in that case either.
No other card is named in this ruling.