The built-in is the most reliable way to create your bootable drive.
Choose the creation method. This automatically selects the optimal media type for your current computer. Select USB flash drive as your destination.
If you already have an Acronis ISO or want to use a specific bootloader, you can use a third-party tool. Creating Acronis Universal Restore on USB Drive
Using the (as opposed to a CD/DVD) is faster, more reliable, reusable, and compatible with modern laptops that no longer have optical drives.