Tamarind juice can be found in Asian or Latin American markets, in small plastic bottles. Tamarind pulp can be found in small “bricks”. If you can only find pulp, mix with about half water to make a prune-juice consistency, removing seeds if any.
Dried shrimp can be found in the spice aisle of Asian or Latin markets. Omit if you can’t find it.
Garlic chives can be found in the produce section of Asian markets. Lacking them, slice the green ends of green onions instead
(Scroll to the bottom of this post for Amazon affiliate links to some brands I like of hard-to-find ingredients)
Find it online: https://hilahcooking.com/pad-thai/