Before 1.21 to summon customizable particles such as "minecraft:dust" and "minecraft:block" you supposted to use "/particle dust r g b s" or "/particle block block_name", but in newest versions, they changed command structure to "/particle dust{color:[r,g,b],scale:s}" and "/particle block{block_state:"minecraft:block_name"}". Also, old variant counts as incorrect, which means that command won't be activated. If someone heard about such programme, please help!