Alcatel Y901NB Modem/Router: Enhancing LTE Network Coverage with Antenna Connection

Hello
I became the owner of the Alcatel Y901NB modem.
In general, I am happy, but I am struggling with the poor coverage of the LTE network. Earlier I had a ZTE MF93D modem with no antennas in the room where it was lying every day had almost perfect 4/5 lines. However, it broke down and I was forced to exchange.

I now have Alcatel outside the house works super 3/4 or 4/4 lines of LTE range, however in the building, in the place where I used the previous modem, the range drops to 1/4 and sometimes disappears completely.

After searching, I found information on the internet that an antenna could be connected to it to improve the range. I found two tiny plugs on both sides of the battery, but they are so deep that I don't know if anything can be connected. I posted photos of these plugins.

And here the questions arise:

Can you really connect the antenna?
What kind of antenna?
With what plug is this antenna?
How to connect it to improve the range?
Are there other ways to improve range beyond the antenna?

Best regards and thanks in advance for your help.

You didn't have any trouble, you bought yourself Alcatel, which is the worst LTE equipment. This equipment is not worth even 1 PLN and nobody oriented will buy it. Alcatel does not provide any support, the equipment is weak and emergency and the lack of external antenna connectors makes it virtually useless. This also applies to Y901, there is practically no use of LTE2600 network (the range in this band is small) or LTE-A with LTE2600 + LTE1800 aggregation. Even just using the LTE1800 is difficult and inside only near the LTE1800 BTS. Poor FW also does not allow forcing LTE / LTE-A bands. No external antenna connectors disqualify this invention. Get it back as soon as possible and buy a stationary LTE / LTE-A router with SMA or MiFi LTE / LTE-A connectors with antenna connectors. preferably Huawei that works with LTEWatchH or Toolbox. These connectors are not antenna but service.

Thanks for the answer.
The fact that I'm green in these subjects has taken a vengeful revenge. Unfortunately, I have no way to return the equipment and I will have to buy another device.
Thanks for clarifying the matter.

Put it up for sale, you may find someone uninformed and buy it for around PLN 200. There are 250 zlotys on the allegro. You can add and buy, for example, a stationary B618, B525 or E5186 and if you care about mobility, it is the MiFi E5786 or E5785.

That's what I'll do, thanks for the hint.