Judgement is a person’s or organisation’s ability to form sensible opinions or make considered decisions, and a judgement is that opinion or decision. In the UK.
And judgment or a judgment is the same thing in US English.
But here’s where the confusion comes in. In the UK, we use judgment solely for a decision made by a judge or a court of law. No e in the courtroom!
“She married him against her better judgement, and it was a mistake she soon regretted.”
*The court made its judgment and he was accompanied to the prison cells.”