import bpy

class MyAddonProperties(bpy.types.PropertyGroup):
    input1 : bpy.props.IntProperty()

class StripSettings(bpy.types.PropertyGroup):
    bpy.types.Sequences.prop1 = bpy.props.BoolProperty(name='Active', default=True)
    bpy.types.ImageSequence.prop2 = bpy.props.BoolProperty(name='Active', default=True)
    bpy.types.Sequences.prop3 = bpy.props.PointerProperty(type=MyAddonProperties)
    bpy.types.ImageSequence.prop4 = bpy.props.PointerProperty(type=MyAddonProperties)

bpy.utils.register_class(MyAddonProperties)
bpy.utils.register_class(StripSettings)