Hi, Our baby is 10/11 months old. He is a very wiggly baby who likes to move around the bed while sleeping. He gets very frustrated when he can’t move freely. We feel he is ready to have a blanket or doona in his cot but would like to know the recommendations before we introduce anything. Currently he is in an empty cot with only fitted sheets and a fitted mattress protector.

Blankets can be used as long as they are light weight & tucked in firmly - not loose. Most older babies/toddlers wriggle/ roll & do not stay under any covers, like blankets.
The general recommendation for bedding for an older child says to wait until a child is in a bed before introducing soft articles like pillow, doona or other soft or loose bedding.
Older babies are at risk of “stacking” objects in a cot to help them climb from the cot.
Red Nose recommends withholding a pillow until baby is out of a cot & over 2 years of age.
https://rednose.org.au/article/can-baby-use-a-pillow-to-prevent-flat-head
https://rednose.org.au/article/at-what-age-can-i-introduce-cot-bumpers-and-pillows