Straight talk with iphone 14 can you use?

In the USA the iPhone 14 comes with no SIM tray so you will have to ask StraightTalk if they provide eSIM.

MVNO's in my country do not provide eSIM even though they iue the networks of the big companies.

Purchased outside USA there is a SIM tray and I see no reason why it would be any different from any other iPhone.

Yes you can.

Find wireless carriers that offer eSIM service - Apple Support

Odd that 'Visible' is not on the above list, I've had Visible service on my iPhone via eSIM for a couple years now.