UK Dividends on Tax return and accounts

[Fox22]

If a company shows dividends in the accounts ending 31st March 2019 for a lesser amount than what is shown on the Self Assessment Tax return for 18/19 do i take off the additional amount of dividends shown in the self assessment from the amount totalled on the end of the 31 March 2020 accounts to get the dividend figure for the 19/20 Self assessment.
The only information that i have is the year end accounts for 2019 and closing trial balance, and 18/19 self assessment.

Advice would be helpful.

Thanks