They're saying you should be in China already because entering China is pretty much impossible at the moment due to covid restrictions. This means schools can only recruit from people already in the country.

Also, unless you have dual citizenship you probably wouldn't meet the visa requirements to teach (teach English that is, maybe you could teach other subjects, I don't know) in China. They have a native speaker requirement that means only people from certain countries will be accepted.

The second point will probably get this post downvoted, any time you mention the native speaker requirement it brings out one or two angry thumbs - they don't seem to understand nobody on this forum makes the rules.....

Anyway, my advice to you would be to look elsewhere. Between China's tough visa requirements and their even tougher covid measures it's pretty much impossible to go there now to teach. The good news is that other countries are dropping their covid restrictions and opening up again so there are probably still opportunities available to you. Good luck.

Don't do it this way at all! You will be scammed handsomely because you are not a native teaher of English.

Asside from Stiggs' asnwer, this it rings the bells for a prospective victim. Even when they make it a work  visa due to the chain of coruption of connections from police and government people, aka guanxie, you will be trashed through many days of misery and dumped, one day at the garbage, because that is what the cycle of saving face means for a scamer. Do not do it! Find the legal way from your home country through the China Embasy.

Nothing is guranteed either on a legally processed working visa from your country . All is based on luck, because good luck is how things turn around here and the bad luck is for naive and stupid people. The good luck comes always on the side of the scammer. The fact that you are being scammed is because you have the call for the bad one.  Sarcasm served it means that  it is your fault tha tyou have bad luck. Somehow it is true but it goes through many shades of grey shades. How could the chance to scam be lost when there  comes the chance! Don't be fooled by the nice messages of apparent good and genuine  will  when they tell you to "come over and we will make your visa a good one". Once in, you have become an easy prey. Many times, the very corect companies who follow the leagal channels practice the scamming as a nature to sharpen again  the dull senses of the survival of the fittest. By that I mean that scamming in China is the measure to prove that you are fit to feed yourself, provide for your family and that brings a sense of face people here need so dearly.

Do not become an easy prey. Do not be a prey at all.

Simple answer, aside from the other comments, you are not qualified for English teaching, and to get into China is very difficult. If you want to experience Asia, I suggest you try some other countries like: Cambodia, Thailand, and Vietnam. 

As others mentioned the reason they are saying that the applicant needs to be in China already is because of the high requirements to come to China. Even if you were able to obtain a "z visa" from the consulate or embassy overseas, there are many requirements you need to meet in order to qualify to board the plane to come to China and a lot of expenses for this. Flights continue to be limited and not cheap. Requirements are regarding taking the approved flights, being in the departure city early (and related expenses), COVID test at the approved lab, etc. Even for Chinese it is a complicated system to navigate to return from overseas.

China is not currently issuing tourist visas and even if they were it would be very difficult or near impossible to obtain a work residence permit if you currently hold a tourist visa and you are in China. There is a difference between a visa that is issued by a Chinese consulate or embassy and a resience permit which is issued in China. 

The only way that coming to China first may make sense both practically speaking and legally speaking is if your spouse is Chinese and you came over based on family reunion.

So, the reality is that you would need the documents to apply for the Z visa and to meet the requirements to board the flight.