Check out patio apple trees (google it); these don't get very large and are suited to growing in containers. You may need more than one tree though for flower fertilisation purposes... link below is to one of these types of trees

https://www.dobies.co.uk/Garden/Fruit/Fruit-Trees/Apple-Trees/Patio-Fruit-Tree-Apple-Red-Sun_253415.htm

Thank you for the information I will look at the website

Many sellers will add a note to their catalogue entry saying Pollination Group A, B or C. You need two trees from the same group because they will flower at the same time. Ocasionally you may see SF for self fertile, in which case you can manage without a second one.

Thank you

Ken Muir is a reputable supplier. Check out his website:
https://www.kenmuir.co.uk/index.php?route=product/category&path=35_43

Blackmoor nursery is another reputable supplier, the web site has details of height & suitability

https://www.blackmoor.co.uk/category/1

If there are apples nearby, in a neighbour's for instance, even ornamental crab apples, they will help the pollination so you may not need to buy a second tree if one already in pace next door

PS unless you have a particular variety in mind I would try & get a variety whose fruit is not readily available in the shops, for instance Royal Gala although a lovely apple is easily obtainable in supermarkets all the year round but unlikely to find a James Grieve because it doesn't travel or keep

Many thanks for the advice

If you look at the Pomona Fruits catalogue you'll see a great many with good descriptions of flavour, uses, height at maturity (mostly 12 feet) from this supplier. They don't normally do the real dwarfing stock but you might get some ideas about variety and flowering time from the catalogue.