is Ecctis letter or english test mandatory?

[asbpp13]

3 Year HSMP + 2 Year Tier 1 + 10 Year ILR While applying naturalisation application,
it says "Ecctis letter that confirms the qualification meets or exceeds the recognised standard of a Bachelor's or
Masters degree or PhD in the UK AND confirm the level of English to which the degree was taught or
researched
I have bachelors degree in engineering from India and my wife bachelor of arts but studied in english medium.

My question, is Ecctis letter mandatory? Can I apply without Ecctis letter and just provide our degree certificates?

[CR001]

You need ECCTIS for a foreign degree.

Or simply do a UKVI approved B1 English test.

This is in addition to the Life in the UK Test obviously.