What are the ways to get a firmware to the KIMAX BS-U35WF?

I have a Kimax BS-U35WF to which I put a firmware of the Kimax BS-U25WF and now only the wifi works and I cannot access it. since I don't know the ip to access because I can't enter neither by SSH nor by SCP. well anyway if someone knows the ip in these cases or if you can enter somewhere to put the correct firmware because a lot would be appreciated. I think I have seen but I no longer know where it could be updated by serial port but I don't know how or where.
I don't need a great tutorial, just clues that I will follow because I don't know where to go

yo tengo un Kimax BS-U35WF al que le puse un firmware del Kimax BS-U25WF y ahora solo funciona el wifi y no puedo acceder a el. como no se la ip para acceder pues no puedo entrar ni por SSH ni por SCP. bueno en fin si alguien sabe la ip en estos casos o si se puede entrar por algun lado para poner el firmware correcto pues se lo agradeceria un monton. Creo haber visto pero ya no se donde que se podia actualizar por puerto seri pero no se ni como ni por donde.
no necesito un gran tutorial simplemente pistas que ya seguire pues ya no se por donde ir

Have you sarched the forum already? There are several topics regarding the BS-U35WF.

Yes, I have been reading a lot on the subject, but since I am not an expert, I have done so until I could continue.
while I could enter through SSH or with openwr Luci or WinSCP, changing ips and getting worse and worse and now I am no way out because I cannot access the router and I saw something connecting it by serial but not if it was this model the BS-U35WF or another. and in case if you could you needed to know how. I have experience with arduinos and ESP32 and other microprocessors and for the latter I put the firmware with the esptool tool and a USB to serial converter, but in this case I need someone to have done it and explain the process to me. I repeat if possible.

Hi it happened to me before .
follow this solution for serial recovery

Thank you very much for the help because I have managed to save my computer and I already have installed a version of Openwr for KIMAX BS-U35WF but this already surpasses me I do not understand anything about the configuration of Luci and although there is a lot of information all is for experts it sounds familiar to me Everything to Chinese I do not know where to start. So I ask the last question where can I get the original firmware that comes from the factory for this equipment? no matter how much I look I can't find it. With that firmware I defended myself and had everything running on my computer.
Now I can neither enter the folders of the built-in hard disk nor access the internal hard disk through USB 3.0 and I already have my head like a hype. If I do not find the original firmware, it seems to me that this device is going to be trash ha ha.
However I repeat I am very very grateful for your help.

Muchas gracias por la ayuda pues he conseguido salvar mi equipo y ya tengo instalado una version de Openwr para KIMAX BS-U35WF pero esto ya me supera no entiendo nada de la configuracion de Luci y aunque hay muchisima informacion toda es para expertos a mi me suena todo a chino no se por donde empezar. por eso lanzo la ultima pregunta donde puedo conseguir el Firmware original el que viene de fabrica para este equipo?? por mas que miro no lo encuentro. con ese firmware me defendia y tenia funcionando todo en mi equipo.
Ahora ni puedo entrar a las carpetas del disco duro incorporado ni accedo al disco duro interior a traves de USB 3.0 y ya tengo la cabeza como un bombo. si no encuentro el Firmware original me parece que este aparato se va a la basura ja ja.
No obstante repito estoy muy muy agradecido por vuestra ayuda.