Bluetooth not connecting to wireless speaker

you likely have to put the bluetooth speaker back into pairing / discovery mode before it will show up

how you go about doing so differ from speaker to speaker, the documentation of the speaker or the website of the manufacturer would contain info about how

or you can just type into google

<bluetooth speaker model name> pairing mode

and you will likely come across some guides

what the AI says

"To put your Bose SoundLink Mini in pairing mode, press and hold the Bluetooth button (the one with the Bluetooth symbol) on the speaker for a few seconds until the light blinks blue and you hear "Ready to pair," then use your device's Bluetooth settings to find and connect to "Bose Mini SoundLink".

Step-by-Step Pairing:

1. Turn On: Power on your Bose SoundLink Mini speaker.
2. Enter Pairing Mode: Press and hold the Bluetooth button (the one with the Bluetooth icon) on the speaker for about 3 seconds.
3. Check Indicator: The Bluetooth light will start blinking blue, and a voice prompt will say "Ready to pair".
4. On Your Device: Go to the Bluetooth settings on your phone, tablet, or computer and turn Bluetooth on.
5. Select Speaker: Find "Bose Mini SoundLink" in the list of available devices and select it to connect.
6. Confirm: The speaker's light will turn solid, and you'll hear a confirmation sound or prompt once connected. 

 "

Bose SoundLink Mini II - Pairing with Android Devices

Connecting a Bluetooth device - Bose SoundLink® Mini Bluetooth® Speaker II

more

Bose mini soundlink pairing mode - Google-

It may help if you can provide us with the make & model of this Bluetooth speaker that you are trying to use with your iPhone.