While the British National Archives at Kew are closed, due to Covid, their records including British military records are free to download if you sign in, all you have to do is create an account.
Another source, though I'm not sure how I found it is The London Gazette newspaper, they have records for medals and important promotions. It is free also, you will probably need to do a lot of searching, it goes by name and date of whatever the event was.
Someone on G2G gave me the link, a few months ago I will look for it and post it here, when I find it
I tried a 1 month membership with the forces war records and was not impressed.
Found London Gazette look under Awards and Accreditations.
Edit: add London Gazette website