dnd 5e – What kind of attack is required to take an Ioun Stone?

Various Ioun Stones include the following bit in their description:

(…) Thereafter, another creature must use an action to grasp or net the stone to separate it from you, either by making a successful attack roll against AC 24 or a successful DC 24 Dexterity (Acrobatics) check. You can use an action to seize and stow the stone, ending its effect. (…)

Notably, a creature trying to grasp or net the Ioun Stone must use their action to make an attack roll. But what kind of attack roll is this?

Can it use a weapon? Is it melee or ranged? Do you add Dexterity or Strength (or neither) to the attack roll? Are you proficient in this attack?

What are the options for a character when they are required to “make an attack roll”?