To add a new option to Avada Dynamic Content Options, you can use fusion_set_dynamic_params filter in your child theme or plugin. This filter is useful for removing or adding options. Here is some sample code.
Each option can have the following arguments.
label = Label which is displayed in options dropdown.
id = Unique option ID.
group = This is used to group similar content types.
default = The default value of option.
options = An array of Avada Builder input option names where this dynamic content can be used.
callback = An array containing callback method name and bool ajax flag
fields = Optional array of additional data fields.
For a better understanding of the available options, please check the set_params function within fusion-builder/inc/class-fusion-dynamic-data.php