IHT403 Gifts from income - where to include dividends in S&S ISA?

itm2

I'm completing the final section of IHT403 - Gifts made as part of normal expenditure out of income. The income declaration has separate boxes for:
- Interest (including PEPs and ISAs)
- Investments

I want to enter dividend income from assets held in an S&S ISA. Not technically "interest", but it's in an ISA. Does anyone know which box I should report it in?

Keep_pedalling

Investments