If reception is still insufficient, there are two possibilities:
1) There are fundamental reception problems at the location, e.g. in a basement apartment. Where nothing arrives, nothing can be received even with great effort. Only an outdoor antenna helps here. 2) Unfortunately, many radios sold today have miserable tuner sections that do not allow noise-free reception even with an antenna.
A special indoor antenna does not provide better reception than a wire dipole. Its only advantage is its smaller dimensions, but it has the disadvantage of constant power consumption. We therefore clearly recommend the wire dipole.
The shop offers dipole antennas with the 75 ohm IEC connector that is common and standardized today. A 240 ohm version is available for older devices.