I don’t know how to get my ECOXGEAR speaker recognized by my Iphone

Press the Bluetooth button on the speaker to change to Bluetooth discovery mode/​pairing mode. Next on iPhone, go to Settings﹥Bluetooth﹥ᴏᴛʜᴇʀ ᴅᴇᴠɪᴄᴇs﹥, and find the discoverable speaker there. Select it to pair and connect. A 4-digit pairing code may be requested. See your device manual if that applies and what the default code is.

A next time, you wouldn’t need to pair again, and the speaker would be remembered to connect to from the Bluetooth settings [ᴍʏ ᴅᴇᴠɪᴄᴇs] directly, or from Control Center.

Connect iPhone to Bluetooth accessories - Apple Support

Play audio from your iPhone on a Bluetooth accessory - Apple Support