Double-checked - and it's still not asking for any documents beyond the three above.
First off, are you sure you have completed the correct application? Because it should ask you for all the documents you were preparing for. If it's not asking for them, you may have selected something incorrectly on the application form.
Secondly, if it is the correct application, even if it doesn't ask for those documents, you MUST still include them. If you only send the 3 documents it is asking for, it will be an automatic visa refusal due to lack of evidence that you meet the requirements.
You need to include (listed as per the relevant upload sections for the UKVCAS website):
Application Documents- applicant's passport
- any previous passport's applicant has held since moving to the UK
- either the consent form or the sponsor's declaration, whichever one it asks for (can't remember which one is required for ILR and which one isn't - FLR(M) requires both, ILR only requires one)
Proof of Identity/Travel History- sponsor's UK passport
- applicant's BRP card
Residence in the UKEvidence of Homeownership- land registry document if you own or rental agreement if you rent
Evidence of monthly housing costs- latest mortgage statement (if you own)
- latest council tax bill
Proof of Cohabitation- 6 official documents in each name dated every 5 months covering the last 2.5 years, from at least 3 different sources
Evidence of Finances- 6 or 12 months bank statements
- 6 or 12 months payslips
- letter from employer
- job contract and P60
Other- marriage certificate
- divorce decrees from previous marriages (if applicable)
- if either of you have any children under 18 living in the UK, you also need their passport(s), birth certificate(s) and a letter dated in the last 3 months confirming their address