It's not an Epiphyllum.

https://en.wikipedia.org/wiki/Pitaya

From the page at the above link.

Pitaya flowers bloom overnight and usually wilt by the morning.[6] They rely on nocturnal pollinators such as bats or moths
for fertilization. Self-fertilization will not produce fruit in some
species, and while cross-breeding has resulted in several "self-fertile"
varieties, cross-pollinating with a second plant species generally
increases fruit set and quality. This limits the capability of home
growers to produce the fruit

I guess that means that my Queen of the Night is also not an Epiphyllum

although it looks very similar to my epiphyllum, but it only blooms at night and is very fragrant, like the pitaya.

I do have fruit on my Princess Kelly epiphyllum

and I have been eating these. Inside, they look very much like dragon fruit and are tasty and a bit tart. I did not hand pollinate this plant, but the flowers were open much longer and had time for others to pollinate them.

Thanks for that ID - I can label that plant now. I knew it was a very common plant, as it propagates very easily and is a prolific grower. However, it does not tolerate sun as much as the other epiphyllum that I have. The confusion I had came from the fact that there are a lot of plants called "Queen of the Night".

Beautiful flowers and fruit, Lars! I missed one of my (our!) epiphyllum's blooming - my neighbor told me about it though. :(

Bloom from Sunday night

photo taken with flash

Photos without flash:

These last two were taken at about 10:00 pm and are lit only by my outdoor light, which fortunately lights up this part of the back yard. I guess the camera thought that there was enough light not to need the flash, but I'm glad I got it both ways.

I hand pollinated this flower at 8 & 10 PM, and so I will see in a couple of months whether I was successful. I have three more buds (in the second photo) which should open later next month, and so maybe I will get something from those also.

I got some help from the tropical fruit forum for hand pollination.

Beautiful!

Lars, I was wondering were you able to self pollinate flowers?

I was able to self pollinate flowers that year, but this year I missed the first one and only noticed it at 8:00 AM - still open but too late to pollinate.

I have another one that should open tonight, and so I am going to set an alarm to remind me, plus I will turn on the outdoor floodlight and open the drapes in my bedroom, from where I will be able to see it. That should be reminder enough. This year I only have three buds making flowers, but with luck, I will get two fruits. I think the first one is already a lost cause.

Somehow or other, the first flower that I got this year appears to be making fruit - and I did not pollinate it in time, and so something else must have done this for me. Anyway, I am happy that I am getting fruit - it looks like I will get three this year. When they get a bit bigger, I will put some protection around the fruit to make sure that critters do not get to them before I do. I think I will build wire cages, but I'm not sure how to attach them without damaging the plant.