Hi Jess, Sorry I have not been able to respond to your PM, but your inbox was full so it didn't allow me to send you a message.
Yes, you can do straddle glide instead or a pike glide and there is no deduction.
nicci1999 In Australia the Glide swing in required for levels 2, 3 and 4 on bars. Level 2 and 3 do a single glide swing and level 4 do two connected Glide swings (unless they can kip). It is different to the USA, the gymnasts must actually complete the glide and let go on the bar and finish behind the bar in a standing position.
Jess, strength is often the issue with a glide swing, can you do a forward roll over the bar and stop your feet from hitting the ground. If you can't then more strength will be required for the move.
When you jump to catch the bar make sure you jump UP to catch the bar not forward, as you catch the bar make sure your legs are tight and your chest is in. Extend your glide out as long as you can.