I went to generate a sitemap for my site which have a lot of internal links as you can see for example:
When generated it doesn’t include any of my internal links but my homepage URL which you can see below:
Then crawled my site with Screaming frog SEO spider and it gave the same result( no internal links found) :
I didn’t block all of my internal links using robot.txt just a few links I don’t want them to be crawled.
I don’t know what’s going on. Please tell me how can I fix this. 
This is my site if you need it.