Formal invitation (notarized) Vs Informal invitation
In temporary residence applications, such as visitor visas, study permits or work permits, the applicant would not be given a second chance to perfect their application or resubmit a document. The onus is on the applicant to establish they are eligible for a visa through evidence.
For instance, You are not required to own a property and submit the title deed. However, Submitting those documents along with your application helps demonstrate your establishment in your home country.