nRF54L15 Tag – BTN1 Overlay
The issue is that sw0 on the nRF54L15 DK maps to P1.13 (Button 0 on the DK), but on the nRF54L15 Tag, BTN1 is connected to P0.00. [Tag Buttons]
So if you're using the DK board target with the Tag hardware, the sw0 alias points to the wrong pin, causing a crash. You need to override it with a devicetree overlay that redefines sw0 to point to P0.00.
Here is the overlay structure you should use:

/ {
    aliases {
        sw0 = &btn1_tag;
    };

    buttons {
        compatible = "gpio-keys";
        btn1_tag: button_0 {
            gpios = <&gpio0 0 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
            label = "BTN1";
        };
    };
};

Key points:

    gpio0 0 maps to P0.00, which is where BTN1 is physically connected on the nRF54L15 Tag. [Tag Buttons]
    GPIO_PULL_UP | GPIO_ACTIVE_LOW is the standard configuration for active-low buttons without external pull-up resistors (consistent with nRF54L15 button hardware). [DK Buttons & LEDs]
    If the existing board DTS already defines a buttons node or sw0 alias, you may need to delete the conflicting nodes first:

/ {
    aliases {
        /delete-property/ sw0;
    };
};

/delete-node/ &{/buttons/};

/ {
    aliases {
        sw0 = &btn1_tag;
    };

    buttons {
        compatible = "gpio-keys";
        btn1_tag: button_0 {
            gpios = <&gpio0 0 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
            label = "BTN1";
        };
    };
};