The Alfornada Gym in southwest Paldea is home to the Psychic-type Gym Leader, Tulip.

How to Reach Alfornada Gym
Go west from Cortondo and follow the path until you reach the "West Province (Area One) - Central" Pokémon Center. Go west from there until the path splits, then go southeast and follow the path. It eventually leads to Alfornada.
Battle Nemona
If you have six gym badges, you will battle Nemona after you enter the gym. She has a level 42 Lycanroc, a level 42 Sliggoo, a level 42 Pawmot, and a level 43 starter (Quaquaval if you chose Sprigatito, Meowscarada if you chose Fuecoco, Skeledirge if you chose Quaxly). She will Terastallize this Pokémon, with the same Tera Type as its usual type. You get 7740 Pokédollars for winning.
Afterward, Nemona gives you 3 Max Potions.
Your Pokémon have been healed and your Tera Orb has been recharged.
Gym Test
In the Gym, talk to the gym staffer behind the counter, then go outside and turn left. You will find Dendra in the yard next to the Gym. Talk to her to and say Yes begin Emotional Spectrum Practice (ESP).
You can press X, Y, A, and B to show different emotions. Repeat the emotions that are shown on the left side of the screen.
Afterward, you will battle Gym Trainer Emily, who has a level 43 Gothorita and a level 43 Kirlia. You get 6020 Pokédollars for winning.
After that, there is another round of Emotional Spectrum Practice.
Next, you will battle Gym Trainer Rafael, who has a level 43 Grumpig, a level 43 Medicham, and a level 43 Indeedee. You get 6020 Pokédollars for winning.
Go to the Pokémon Center to heal up your Pokémon, then go back to the gym lobby and talk to the staffer behind the desk if you are ready to battle the Gym Leader.
Psychic Gym Leader Tulip, the Bewitching Beautician
Tulip has a level 44 Farigiraf, a level 44 Gardevoir, a level 44 Espathra, and a level 45 Florges that she Terastallizes with Tera Type Psychic. You get 8100 Pokédollars for winning.
You will get a Gym Badge. Check the Gym Badge Effects page to see the level of Pokémon that will listen to you and be easier to catch, or open the Map App or Pokédex App and press X, then select Profile, then press A to see the effects of your current badges.
You also get a TM120 Psychic.
New Sandwiches
A new Gym Badge means new sandwich recipes. Be sure to stop by any Every Wich Way and talk to the person in front of the counter to learn some new recipes.