Biometric/Spouse 2.5 extension/renewal

Hi all,
I arrived over 2 years and my biometric card/spouse visa is due to expire in january and I will need to renew for another 2.5 years.
I've heard conflicting things so I'd appreciate confirmation on:
- when's the latest I need to apply for renewal? can I do it now or wait until December?
- is the gov website the correct and only place that I need to apply (https://www.gov.uk/uk-family-visa)? if there's another website do let me know.
- will i need to go anywhere for an interview or give evidence or is everything submitted online/post.

if anyone has done this recently do let me know if there's anything else i need to know ))
thnks

- when's the latest I need to apply for renewal? can I do it now or wait until December?

Your residnece clock starts counting from the date you entered the UK in a spouse visa (not a 6 month fiance visa). You should apply no sooner than within 28 days if reaching 30 months residence on a spouse visa, counted from the date you entered the UK. The latest you can apply is the date your visa expires. The date if application is the date you submit and pay online.

- is the gov website the correct and only place that I need to apply (https://www.gov.uk/uk-family-visa)? if there's another website do let me know.

Correct website.

- will i need to go anywhere for an interview or give evidence or is everything submitted online/post.

There is no interview. You apply online and upload your documents online to the ukcvas portal before your biometric appointment.