This thing is terrifying. It's cheap Cheese shovelware straight of Alibaba, which means there's nothing safe about it because it uses 230V internal to the strip. I'm generally willing to trust low-voltage stuff, but putting AC mains on those LED strips is bonkers.
Never buy electrical gear on Amazon, for the same reason you wouldn't buy electrical gear on eBay. Amazon opened up their store to 3rd party sellers, and so most gear on Amazon is exactly the same crud as found on eBay.
It is an "LED strip" of the style one is used to seeing in 12V or 24V (which allow the strip to be cut every 50mm or 100mm respectively)... however, this one is 230V internally. Really. Note how it can only be cut every 1 metre.
That is because these LED strips are constructed as 3 LEDs and a resistor every 50mm, and that unit takes 12 volts. Thus, 12 volt strips get cut intervals every 50mm. 24 volt strips get cut intervals every 100mm.
The lump in the cord is far too small to be a low voltage power supply. It may be a bare diode rectifier which is even scarier because now we're dealing with DC, which has much more dangerous characteristics.
Since the product is not safety-rated for sale in your country, you should feel absolutely privileged to send it back angrily.
I cannot advise on how to dim this, because a) continuing to use it would be insane, and b) I am really not sure which internal technology they are using. It is definitely incompatible with any of the dimmers used in normal 12V or 24V LED strips, since those are expecting 24 volts at most.
My advice would to re-do this with normal 12-volt or 24-volt LED strips, which will allow you to use normal 12-24 volt LED-strip dimmers which use PWM technology. That is an excellent dimming tech that will do what you want.
With 12 volt low voltage stuff, safety is far less of a concern, so dodgy sources like eBay/Amazon are not as great a risk.