employment termination lumpsum within an ACAS agreement

Good morning In August 2022 my contract was terminated by my previous employer, in May 2023 after a long negotiation, I received a lumpsum of 46K in relation to the termination of the contract, this was within an ACAS agreement. My previous employer did not provide a P45 nor a P60 for this lumpsum. However, they provided a payslip showing the GBP 46K gross pay, of which 16k taxable pay and a tax deducted of GBP 6,050.25 (much higher than what I should have paid). In which section should I declare the lumpsum in my self assessment tax return? Should I indicate the full 46K lumpsum or only the 16k taxable amount? Where should I indicate the 6,050.25 tax deducted ? Should I provide the ACAS agreement with my self assessment tax return? Thank you in advance

Hi
Please refer to Other UK income - page 3, box 5 onwards.