The information on testing requirements is in the application. You fill out the form until you reach the information. I was at Anticosti in the first week of October. The ArriveCanada process was pretty easy less some system problems (Arrive Canada did not like Microsoft Edge of Firefox when I put my data into the system - this may have been corrected), When I arrived at the border my vaccine info was on the system and I showed them documentation of my test results (PCR test). The whole thing took 5 minutes. Just make sure you have everything done. As a just in case I brought additional paper copies of my documents.

The following is from the ArriveCanada website and identifies acceptable tests.

To qualify as a fully vaccinated traveller, you must also follow these requirements:
1. Get a pre-entry test (accepted types and timing)
Who must take a pre-entry test

All travellers 5 years of age or older, regardless of citizenship or vaccination status, must:

provide proof of a COVID-19 negative molecular test result to enter Canada OR
proof of a previous positive test result taken between 14 and 180 days.

Types of pre-entry test

Rapid antigen tests aren't accepted.

Accepted types of molecular tests

PCR - Polymerase chain reaction
Nucleic acid test (NAT) or Nucleic acid amplification test (NAATs)
Reverse transcription loop-mediated isothermal amplification (RT-LAMP)

These tests use methods such as a nasopharyngeal (NP) swab, nose swab, or saliva sample.
Other acceptable types of tests

RT-PCR – reverse transcription real time PCR
Quantitative PCR (qPCR)
Isothermal amplification
Droplet digital PCR or digital droplet PCR (ddPCR)
Transcription-mediated amplification (TMA)
RNA (Ribonucleic acid)
Ct (cycle threshold)
CRISPR
Sequencing
Next generational sequencing (NGS) or whole genome sequencing (WGS)
Oxford Nanopore sequencing (LamPORE)
Detection of the N gene
Detection of Orf1a/b
Detection of the S gene
Detection of the E gene
Detection of the RdRp gene