Prove that the following language is not regular: $\{0^i1^j : i \neq j\}$ [duplicate]

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• How to prove that a language is not regular? 10 answers

I was trying to approach this proof, after multiple reads and attempts I am getting nowhere. If someone could help me out that would be great. Should I use the pumping lemma, if so how show I start, what word should I choose? Or should I use closure-properties and if so what irregularity should I show? I am genuinely so confused. Any help is appreciated.