Hi @jamesjewess
Chance are that the battery has failed and would need to be replaced.
Does the phone indicate that the battery is charging when a known working, compatible charger is connected to the phone?
If it does, keep the charger connected for at least 2-3 hours and check if the battery now starts to charge. Allow it to fully charge before attempting to turn on the phone.
If it doesn't indicate that it is charging or even if it does but never charges and starts, replace the battery and check if that resolves the problem.
Here's a [https://www.youtube.com/watch?v=4ZoYHwjlonc|video] that may help.
Search online for [https://www.google.com/search?client=firefox-b-d&q=HE340+battery|HE340 battery] to find battery suppliers that suit you best.