Your potion needs an effect. What about a simple "Instant Health" (6
) effect or a little bit of "Strength" (5
)?
Have a look on http://minecraft-helpandinfo.weebly.com/potion-effects-ids.html to find out about all possible values and enter the corresponding potion effect name in the following field.
How "strong" should be the effect of the potion? We need a amplifier value here.
But we are not done yet. How long should the potion effect last (in ticks)?
Last one: Give a name to you potion, so players know what potion they are going to buy.