A land crossing between Canada and the US is where you flagpoll. You don't visit the US, though. Instead, you let the US border agent know that you want to change your status in Canada. They often send you back to Canada after refusing to let you into the US. You apply for the new status once in Canada.

Flagpoling could occur for several reasons. For example,

applying for a work permit,
receiving a study permit,
landing in Canada as a permanent resident, or
extending the stay as a visitor.

Who may flagpole for a work permit?
You may apply for a work permit at a port of entry if you are exempt from visas for visiting Canada. Of course, people could be visaexempt for any of the following reasons:

Their nationality (citizenship)
The documents they hold
The purpose of the visit
Do not flagpole for a work permit if you do not fall under any of these groups. If unqualified, you could face one of the following problems:

The officer allows you to enter Canada but advises you to apply online or by paper after the entry
They may advise you to apply after leaving Canada
The officer issues a removal order for you
In rare cases, you may face detention

What kind of documents do you need?
If you are eligible for flagpoling for a work permit, you need to have all the necessary documents with you at the time of application, namely:

Identity documents, such as passport and driver’s licence
The letter of LMIA or documents that show you are exempt from LMIA
Offer of employment
Some documents that prove your employer is legitimate
Your CV
Some documents that show the offer of employment is genuine
Documents that show you are the right candidate for the job
Medical examination report if your job requires going through the medical examination
Police certificate reports show you have no criminality issues. Police certificates are optional for most people
proof of legal status in Canada, such as a work permit or study permit
Although not mandatory, I highly recommend the following documents:

Another governmentissued ID other than your passport, and
two immigration photos, and
any other documents that support your work permit application
If you have implied status, you need to take proof of your implied status to the port of entry, namely:

Confirmation of receipt of the extension application, and
receipt of payment, and
any other documents that show you have implied status.
If any of the documents are not in English or French, make sure to translate them to one of them. Of course, use the services of a certified translator only.

What kind of documents do you need?
If you are eligible for flagpoling for a work permit, you need to have all the necessary documents with you at the time of application, namely:

Identity documents, such as passport and driver’s licence
The letter of LMIA or documents that show you are exempt from LMIA
Offer of employment
Some documents that prove your employer is legitimate
Your CV
Some documents that show the offer of employment is genuine
Documents that show you are the right candidate for the job
Medical examination report if your job requires going through the medical examination
Police certificate reports show you have no criminality issues. Police certificates are optional for most people
proof of legal status in Canada, such as a work permit or study permit
Although not mandatory, I highly recommend the following documents:

Another governmentissued ID other than your passport, and
two immigration photos, and
any other documents that support your work permit application
If you have implied status, you need to take proof of your implied status to the port of entry, namely:

Confirmation of receipt of the extension application, and
receipt of payment, and
any other documents that show you have implied status.
If any of the documents are not in English or French, make sure to translate them to one of them. Of course, use the services of a certified translator only.

https://www.cbsaasfc.gc.ca/dorb/ser...