Hi HenrySS_149,
Welcome to the Apple Community.
An iPad will generally do faithfully whatever it is set up to do ... (the alarm must have a source ... possibly set accidentally ?)
Thank you for including your iPad's iOS in your post.
Apple support have articles online (blue links below) for iPad OS12 that may help track down that alarm.
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Set an alarm or bedtime schedule on iPad – Apple Support
eg: (1) Check the Clock Alarm is not still set to "repeat" on the various days of the week (if so Tap Edit, and delete the setting)
and
(2) Tap Bedtime and check sleep or wake times have not been accidentally set
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Schedule reminders on iPad – Apple Support
You might want to check there is no "every day" reminder scheduled in a reminder list
ie: Open a list, swipe left on the reminder, then tap More.
Or
To turn off reminder notifications, go to Settings > Notifications > Reminders,
then turn off Allow Notifications.
To silence notifications temporarily, go to Settings > Do Not Disturb, then turn on Do Not Disturb.
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Change or turn off iPad sounds – Apple Support
If you still haven't been able to turn off the alarm
You might recognise / identify (delete?) the sound that is used for the alarm ... or could possibly a clue to the alarm source..
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You might want to try asking Siri to :"Turn off the 7.45 am every day alarm":
Temporarily silence incoming calls, alerts, and sound effects, turn on Do Not Disturb. overnight.
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More Resources:
iPad iOS 12 user guide:
To see detailed articles: click on "Table of Contents" at the top of the welcome page,
Welcome – Apple Support
Or
iPad - Official Apple Support
All the best :-)