Viagra increases testosterone?

I wonder if this relates to other things that increase late-life testosterone like red meat (unprocessed)?

https://www.alzdiscovery.org/cognitive-vitality/blog/does-ea...

I've always thought about how big of a role testosterone plays in later-life health and I wonder why doctors don't prescribe it to restore testosterone levels to a normal (for a younger person) level to prevent osteoporosis and other hormone-linked diseases. Not saying this conclusion in the article is related to testosterone, but I have to speculate on it.