Extension application for spouse visa

Hi
I am British passport holder and my husband and 3children came in uk Apr2019.Now we are going for further leave to remain extension of Visa at 5years route what the documentation we need at the time of application. Anyone guide me plz

https://www.gov.uk/uk-family-visa/partner-spouse

https://www.gov.uk/government/publicati ... -form-flrm

https://assets.publishing.service.gov.u ... .0-ext.pdf

https://assets.publishing.service.gov.u ... 7.0ext.pdf