Hi I have a 26month old boy. He is still in a cot, but I’m guessing he will move to a bed around 3. Is it okay to introduce a pillow and dooner now in his cot. He tends to ask for a pillow or blanket if so are there special pillows for toddlers

There is information that says to withhold a pillow for babies less than 2yo.
However, Red Nose also recommends waiting till a child is in a bed before introducing a pillow.

Older babies in a cot can be at an increased risk of a sleeping accident by using pillows and bumpers (& large soft toys) as a step to climb up and fall out of the cot. It is safer to wait until the child starts to sleep in a bed before introducing a pillow or other soft bedding.

https://rednose.org.au/article/at-what-age-can-i-introduce-cot-bumpers-and-pillows

Keep the cot free of large soft toys, pillows, bumpers, activity centres and anything else that could be ‘stacked’ to assist a young child/toddler to climb out of the cot.

https://rednose.org.au/article/can-my-baby-have-a-soft-toy

Red Nose does not recommend placing a pillow where baby sleeps unobserved. It is safer to wait until the child starts to sleep in a bed before introducing a pillow. The Australian government states it is safer not to use a pillow at all for children under two .

https://rednose.org.au/article/pillow-use