You only need to submit evidence of residence if:

You have been offered pre-settled status despite having lived in the UK 5 years or longer and you want to get settled status; or
You have been asked to provide it after starting your application, because the automated checks did not find enough data.

You don't need to provide evidence for your entire UK residence, just enough to show whether you qualify for settled or pre-settled status.

What you need to provide

1 document dated before the end of 2020 and, if this is dated over 6 months ago, also a document dated in the last 6 months

Evidence for 6 months out of every 12 month period of residence for settled status.

Your documents must show you started living in the UK by the end of December 2020.

All documents must be dated and have your name on them.

You should only provide 1 piece of evidence to cover each month or longer period of time.

You can upload a maximum of 10 documents.

Each document must be no more than 6MB in size.

The evidence provided must show that you have been living in the UK, for example, bank statements should show transactions in the UK, rather than just direct debits, interest payments, dividends, etc.

If you have any issues uploading documents or need to upload more than the allowed amount of files, please note the tips about uploading more than 10 documents in this post Uploading documents to prove residence - UKCEN Citizenship and Residence for European Nationals and their families if you have any issues with uploading the evidence contact the resolution centre.

You should be able to send evidence by email, but you can only do so after being instructed by the resolution centre.

How is evidence considered?

A document with a single date on will count as proof of residence for that month only, for example, a monthly electricity bill, an official letter, or a GP appointment card.

Documents with a start and end date will cover the period between the two dates.

Use documents that cover longer periods of time if you can, such as annual bank statements, council tax bills or university letters and certificates. This means you will not need to submit as many documents.

Where no data is found, applicants are usually asked for evidence for the last 7 years. This can be disconcerting for those who've not been here 7 years, but there's no cause for concern, you only need to provide evidence for 5 years, the Home Office has explained that this is done in case someone hasn't got evidence for the most recent periods.

See: Documents to be used in evidence.
Source: Evidence of residence.