For sponsoring Dependent Child, the necessary forms are available through this link.
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/application-forms-guides/guide-5289-sponsor-your-spouse-common-law-partner-conjugal-partner-dependent-child-complete-guide.html
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/application-forms-guides/guide-5289-sponsor-your-spouse-common-law-partner-conjugal-partner-dependent-child-complete-guide.html