Put half a cup of cheap baking soda and then pour a cup of cheap vinegar. It will fizz up. Then pour a kettle of hot water into drain, You may have to do this several times.
If necessary, dip out water and pour down sink to make access to tub drain easier.
You probably need to remove hair anyway cuz it finds its way down drain regardless.
Unscrew top of drain and use screwdriver or big tweezer to pull the hair out.
I prayed for this in Jesus name. Amen.
p.s. Read Pradmin's blog. The software was upgraded. The site is faster and you do get used to it.