What exchange rates should be used

HMRC Admin, I've sold 150 US shares (same company and same class) which were purchased in different dates and years, for example, 60 shares purchased in Dec 2020, 90 shares in Feb 2021. When filling in my tax return, do I need to use different exchange rates at the acquisition dates for calculation of gain or loss? Or just use the exchange rate on the date that they were sold? Thanks.

Hi,
As this would be classed as a S104 holding please refer to below link, example 3.
Shares and Capital Gains Tax (Self Assessment helpsheet HS284)
Thank you.