How to add Form Propeties and Assignment in BPMN JS properties panel

1) How can i add multiple form properties to Start Event?
2) How can i add Fixed values as assignee under Assignment for User Tasks?
3) How to add form properties to user tasks?

You are refering to a custom properties panel to accomplish these things? What did you try already?

Hi nikku,
I am able to add custom attribute ,below is my code :

 getTabs(element) {
        console.log(, 'Creating property tabs');
        return this.bpmnPropertiesProvider.getTabs(element)
                id: 'custom',
                label: this.translate('Custom'),
                groups: [
                        id: 'customText',
                        label: this.translate('customText'),
                        entries: [
                                id: 'customText',
                                label: this.translate('Assignee'),
                                modelProperty: 'assignee'

I want to add extensionElements for adding form property.