English language requirements

I was recently granted Indefinite Leave to Remain (ILR) and plan to apply for British citizenship next year, however, I would like clarification regarding the English language requirement, as I previously achieved an IELTS C1 score and submitted that certificate with my initial Skilled Worker visa application five years ago, and I would like to know whether the same certificate can be relied upon for my citizenship application or whether I must sit a further English language test prior to applying. In addition, I note that during my ILR application there was no specific question concerning the English language requirement, and I would be grateful for guidance on how this affects the citizenship stage. Thank you.

Did you complete the LIUK test for your ILR application?

Yes, I have completed the Life in the UK test and submitted it when I applied for ILR.

You can explain that and reattach the same test then.