Tag alt in image

I need to add alt tags to images.
I have looked in wpgeodirectory.com/support, I found a lot, but not the solution.
I think I have wordpress settings well

1) I gave name to image “beach-head-white-portoferraio-elba-3.jpg” as I wanted “tag alt” but does not even appear the “tag alt”.
This what we see is: <div data-src = “https://virtualelba.it/elba/new/wp-content/uploads/2019/01/23785_spiaggia-capo-bianco-portoferraio-elba-3.jpg” class = “geodir_thumbnail geodir_lazy_load_thumbnail” title = “beach-cape-white-portoferraio-elba-3” air-label = “beach-cape-white-portoferraio-elba-3” style = “background-image: url (& quot; https : //virtualelba.it/elba/new/wp-content/uploads/2019/01/23785_spiaggia-capo-bianco-portoferraio-elba-3.jpg"); opacity: 1; “> </ div>

2) I am the only administrator of the site.
3) It is possible castom geodirectory to insert tag alt

WordPress: 5.0.3
Template: Directory Starter Child
GeoDirectory plugin for WordPress Version 1.6.37
GeoDirectory Location Manager plugin Version 1.5.63