How can we create a safe sleep environment for babies?”

What age of babies are you referring to?
Are you contacting as a parent, a Health Professional or a Child Care Educator?

Here are a couple of references for you.
https://rednose.org.au/article/what-is-a-safe-sleeping-environment
https://rednose.org.au/article/what-do-the-safe-sleep-recommendations-mean

What State are you from?
Let me know your responses so I can reply more specifically to you.

In my opinion,  to create a safe sleep environment for babies, always place them on their back to sleep on a firm, flat mattress in a clear, smoke-free sleep space like a cot or bassinet, free from loose bedding, pillows, bumpers, or toys, and maintain a comfortable room temperature

The babies are below 1 years old,

I am a Child Care Educator

Also important to follow recommendations from ACECQA & local regulator who do not allow babies sleeping in child care Services to be placed for sleep in a bassinet.

https://www.acecqa.gov.au/resources/supporting-materials/infosheet/safe-sleep-and-rest-practices