It takes time to get the first ones. After getting a few, it is possible to slowly increase the traffic over a few years. People who live in areas with a lot of hummer traffic can attract them quickly, but people who are off the hummers' beaten path have to be patient and consistent. You may only get a few this year, but keep trying.

Consistency is the big factor. Sugar water sours fast in a warm/hot environment. Hummers leave if they taste sour juice. Only put up small amounts of juice till you have enough birds to drink more. About every third day take the feeder down, thoroughly clean it with something that will kill all bacteria, thoroughly rinse it, then put fresh clean juice in it. Be consistent. Every hummer that gets good juice at your feeder will visit again. If it is migrating, you will see it and it's offspring in the late summer as they head south. If it is nesting, you will see it all summer.

Presently I am keeping three feeders up. I clean and refill one of them every day.

I am taking the feeder inside, pouring out the old sugar water, and filling/refilling it with hot water several times every 3-4 days. I read that I shouldn't use soap to clean it, hence only the hot water. Then I dutifully mix more 1:4 sugar:water liquid (I store the extra in the refrigerator) and fill the feeder halfway, as you see in the photo. No hummers yet.

Just keep it up. They will come.

Do you have a set of scrub brushes? I have 4-5 glass feeders similar to yours. They need to be scrubbed with the hot water.