[RayDcosta]

it probably does not have a /enter command.
when using a script you should know what it has and what it doesnt.
i suggest you try something like (crouch button - default 'C' or positive-response button -- default 'Y') or the button that u use to enter / exit vehicles (default - F or ENTER)
if none of this works, open the .pwn file of the script and begin searching.
cheers
hope i helped you