While to keep your Canadian PR status you must be physically present in Canada” at least 730 days in every five years, to apply for Canadian citizenship you must be physically present in Canada for at least 1095 days during the five years. There is an exception to these general rules for the spouse or common-law partners of Canadian citizens who lived outside Canada.
People get confused about the exception of being eligible to apply for Canadian citizenship without being physically present in Canada because of being with Canadian citizens as a spouse or common-law partner.
The truth is there are two different rules:
Eligibility to meet the residency obligation for keeping Permanent Residency status without 730 days physically present in Canada because of being accompanying a spouse, a common-law partner who is a Canadian citizen.
Eligibility to meet the physical presence requirement of citizenship with 1095 days in Canada because of being lived outside Canada with your Canadian spouse or common-law partner or permanent resident spouse, common-law partner, or parent who was employed in or with the Canadian Armed Forces, or federal public administration, or public service of a province or territory.
 “Did you have an acceptable reason for being out of Canada?” read online https://irb-cisr.gc.ca/en/legal-policy/procedures/Pages/residency-obligation-outside-canada.aspx
 “Can I count any time I’ve spent outside of Canada toward the physical presence requirement when applying for citizenship?” read online https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=370&top=5