give @s[advancements={blazeandcave:nether/stem_research={crimson_stem=true}}] minecraft:crimson_stem 2
tellraw @s[advancements={blazeandcave:nether/stem_research={crimson_stem=true}}] {"color":"green","text":" +2 ","extra":[{"translate":"block.minecraft.crimson_stem"}]}

give @s[advancements={blazeandcave:nether/stem_research={warped_stem=true,crimson_stem=false}}] minecraft:warped_stem 2
tellraw @s[advancements={blazeandcave:nether/stem_research={warped_stem=true,crimson_stem=false}}] {"color":"green","text":" +2 ","extra":[{"translate":"block.minecraft.warped_stem"}]}