We literally have no idea you would appreciate that. Some people really don't like that.
Ask for them or say you want flowers. Even just asking something like "so when are you going to buy me flowers as a random romantic gesture?" Is a clear enough indication that flowers should be bought.
I know, you just want him to do it spontaneously, that isn't how guys work. Maybe the first date, anniversary, birthday, or Valentine's a guy will do flowers unprompted. First date is least likely because it is a burden to have to deal with flowers if he isn't picking you up from your place and a lot of people don't feel comfortable telling a guy where you live with a first date. Are the flowers going to sit in the car? Are we bringing the flowers everywhere like some sort of botanical third wheel?
Guys are practical to a fault. Flowers are such unnecessary and pointless things to spend money on outside of the aforementioned occasions that buying flowers otherwise are such a rediculous concept to the male mind. The money can be used for other things of use and the flowers are just going to die, so what is the point of that waste and lack of utility?
That isn't even touching on how such a traditional romantic gesture is possibly some sort of conservative toxic masculinity gender role red flag that supports slave wages for undocumented migrants which you will get indignant over and he gets his nice romantic gesture turned into a bite in the ass.
So just say something if you want something, that is how guys work. Don't hint. Don't demand. Just say what you want and a good man will satisfy the primal need to provide and make it happen. "I would love it if you brought me flowers and some chocolates randomly. That would be so romantic and sweet." Then you just have to wait, probably until the next time you see him because your need of flowers and chocolates has been elevated to a super important thing and making you wait for some other time would be poor providing for your needs or you may think he forgot and doesn't care.
Your eyes lighting up and your smile will chisel in stone that flowers and chocolates are an easy way to cheer you up and it will be done again randomly or to raise your spirits. Once you stop responding with enthusiasm, he will think that it stopped working and will probably stop, so always be excited and happy to get flowers and chocolates to renew your ticket.