I personally prefer DOT4 over 3 for better performance, but you may have to replace it more often as it absorbs moisture faster. Any bottle of DOT4 synthetic will do the trick. Pick up a liter and that should be enough.
If you’re feeling bougie, give ATE SL6 a shot. It’s low viscosity (class 6) so it should supposedly perform better than standard DOT4 fluid. It’s a track formulation and overkill for everyday needs. It worked well in my ‘13 CX-5 and continues to work well in my ‘21 RAV4 hybrid. Will likely go with that this year for my ‘23 Turbo. For my truck though? Couple liters of Prestone DOT4 from Walmart.