It is very good for its price. My only problem is that it often loses connection with the Wi-Fi, but it could also be due to the line.

Do you want to print fast, easily, and high-quality black and white A4 documents? Do you want it to be a multifunctional machine at the same time? Do you want to spend as little money as possible? Do you not care about double-sided printing? Buy the HP MFP 137fnw. It's cheap, there are many no-name toners on the market, easy connection to all PCs on the same network, and high-quality prints. I was hesitant because of the better reputation and reviews that Brother & Xerox multifunction machines had, but I was 100% satisfied.

I have it for only two days but I am completely satisfied, quality construction, easy installation, prints quite fast and finally the worry of ink running out after a month is gone. It's worth 100% if you want a black and white printer with a scanner. I also bought an additional GENUINE toner for 1000 pages for 42 euros. CAUTION: what it comes with is for 500 pages.
Also, a note is that if you have an old mobile device with Android 5 and below, the application does not work, it requires Android 6 and above.

Update 16/4/2021
After doing some research on toner and because the new genuine one is a bit expensive, I decided to try refilling the genuine toner myself. I bought plain graphite for 7.50€, solved the toner, did a complete cleaning, refilled it, and sealed it again. You don't need a new chip, it just displays "low toner" on the screen but prints normally! I'm already at 500 pages and it's going strong!! I refilled both genuine toners for only 15€!!
https://www.youtube.com/watch?v=3BRrjw7LGW0&list=PLFZbLpZ1iirxpmtY_yVIZo11DjNYQpEpT&index=50