In a medium bowl, whisk together beer, vinegar, seasonings, and brown sugar. Pour mixture over pork and flip to coat.
Place cover on instant pot and seal. Cook on high pressure for 65 minutes. Allow natural pressure release for 10 minutes and manually release the pressure.
Remove top and shred the pork. Pour your favorite bbq sauce of the pork and gently stir to coat. Serve immediately, or use keep warm setting till you are ready to serve on bun and top with additional BBQ sauce, if desired.
The instant pot will have a bit of liquid in it, and if you prefer a thicker coating or do not want to top with sauce, I recommend draining some liquid before returning the shredded meat to the instant pot.